Per P0 reqs add launch points + make download obvious. Also misc copy edits.

BUG=none
R= [email protected], [email protected], [email protected]
TEST=none
NOTRY=true
(documentation only change)

Priority list copied here for reference:
P1 But written by different engineers, very uneven quality and voice.
P2 Some documentation could be expanded.
P0 The ramp-in for new users could be improved.
P0 The landing page isn't "cool", it doesn't make developers want to jump in and use it.
    Could we have a more github-like thing that gets people started quickly?
    Could we have a narrative intro?
    We just bought the pna.cl domain, we should use it!
P3 We think it's pretty important to keep the deep-dive in there (e.g. sandbox internals, bitcode reference).

Review URL: https://codereview.chromium.org/476793002

Cr-Commit-Position: refs/heads/master@{#291696}
diff --git a/native_client_sdk/doc_generated/overview.html b/native_client_sdk/doc_generated/overview.html
index b9d48dbc..7886ddc 100644
--- a/native_client_sdk/doc_generated/overview.html
+++ b/native_client_sdk/doc_generated/overview.html
@@ -42,50 +42,44 @@
 <h2 id="why-use-native-client">Why use Native Client?</h2>
 <p>Native Client open-source technology is designed to run compiled code
 securely inside a browser at near-native speeds. Native Client puts web
-applications on the same playing field as traditional (locally-run)
-software&#8212;it provides the means to fully harness the client&#8217;s computational
-resources for applications such as 3D games, multimedia editors, CAD modeling,
+applications on the same playing field as desktop software&#8212;it provides the
+means to fully harness the client&#8217;s computational resources for applications
+such as 3D games, multimedia editors, CAD modeling,
 client-side data analytics, and interactive simulations.
 Native Client also aims to give C and C++ (and eventually other languages) the
 same level of portability and safety that JavaScript provides on the web today.</p>
-<p>Here are a few of the key benefits that Native Client offers:</p>
+<p>Important benefits of Native Client include:</p>
 <ul class="small-gap">
-<li><strong>Graphics, audio, and much more:</strong> Run native code modules that render 2D
+<li><strong>Graphics, audio, and much more:</strong> Running native code modules that render 2D
 and 3D graphics, play audio, respond to mouse and keyboard events, run on
 multiple threads, and access memory directly&#8212;all without requiring
 the user to install a plugin.</li>
-<li><strong>Portability:</strong> Write your applications once and you&#8217;ll be able to run them
-across operating systems (Windows, Linux, Mac, and Chrome OS) and CPU
-architectures (x86 and ARM).</li>
-<li><strong>Easy migration path to the web:</strong> Many developers and companies have years
-of work invested in existing desktop applications. Native Client makes the
-transition from the desktop to a web application significantly easier because
-it supports C and C++.</li>
-<li><strong>Security:</strong> Native Client uses a double sandbox model designed to protect
-the user&#8217;s system from malicious or buggy applications. This model offers the
-safety of traditional web applications without sacrificing performance and
+<li><strong>Portability:</strong> Writing your applications once and running them on operating
+systems (Windows, Linux, Mac, and Chrome OS) and CPU architectures (x86 and
+ARM).</li>
+<li><strong>Easy migration path to the web:</strong> Leveraging years of work in existing
+desktop applications. Native Client makes the transition from the desktop to a
+web application significantly easier because it supports C and C++.</li>
+<li><strong>Security:</strong> Protecting the user&#8217;s system from malicious or buggy
+applications through Native Client&#8217;s double sandbox model. This model offers
+the safety of traditional web applications without sacrificing performance and
 without requiring users to install a plugin.</li>
-<li><strong>Performance:</strong> Native Client allows web applications to run at speeds
-comparable to desktop applications (within 5-15% of native speed).
-Native Client also allows applications to harness all available CPU cores via
-a threading API; this enables demanding applications such as console-quality
-games to run inside the browser.</li>
+<li><strong>Performance:</strong> Running at speeds comparable to desktop applications (within
+5-15% of native speed). Native Client also allows applications to harness all
+available CPU cores via a threading API; this enables demanding applications
+such as console-quality games to run inside the browser.</li>
 </ul>
 <h2 id="common-use-cases">Common use cases</h2>
 <p>Typical use cases for Native Client include the following:</p>
 <ul class="small-gap">
 <li><strong>Existing software components:</strong> With support for C and C++, Native
-Client enables you to reuse existing software modules in
-web applications&#8212;you don&#8217;t need to rewrite and debug code
-that&#8217;s already proven to work well.</li>
+Client lets you to reuse existing software modules in web applications. You
+don&#8217;t need to rewrite and debug code that already works.</li>
 <li><strong>Legacy desktop applications:</strong> Native Client provides a smooth migration
 path from desktop applications to the web. You can port and recompile existing
 code for the computation engine of your application directly to Native Client,
-and need repurpose only the user interface and event handling portions to the
-new browser platform. Native Client allows you to embed existing functionality
-directly into the browser. At the same time, your application can take
-advantage of things the browser does well: handling user interaction and
-processing events, based on the latest developments in HTML5.</li>
+and need rebuild only the user interface and event handling portions for the
+browser.</li>
 <li><strong>Heavy computation in enterprise applications:</strong> Native Client can handle the
 number crunching required by large-scale enterprise applications. To ensure
 protection of user data, Native Client enables you to build complex
@@ -103,15 +97,14 @@
 <li><strong>Any application that requires acceleration</strong>: Native Client fits seamlessly
 into web applications&#8212;it&#8217;s up to you to decide to what extent to use it.
 Use of Native Client covers the full spectrum from complete applications to
-small optimized routines that accelerate vital parts of web apps.</li>
+small optimized routines that accelerate vital parts of web applications.</li>
 </ul>
 <h2 id="how-native-client-works"><span id="link-how-nacl-works"></span>How Native Client works</h2>
-<p>Native Client is an umbrella name for a set of interrelated software components
-that work together to provide a way to develop C/C++ applications and run them
-securely on the web.</p>
+<p>Native Client is an umbrella name for a set of related software components that
+provide a way to develop C/C++ applications and run them securely on the web.</p>
 <p>At a high level, Native Client consists of:</p>
 <ul class="small-gap">
-<li><strong>Toolchains</strong>: collections of development tools (compilers, linkers, etc.)
+<li><strong>Toolchains</strong>: Collections of development tools (compilers, linkers, etc.)
 that transform C/C++ code to Native Client modules.</li>
 <li><strong>Runtime components</strong>: components embedded in the browser or other
 host platforms that allow execution of  Native Client modules
@@ -123,9 +116,9 @@
 (PNaCl, pronounced &#8220;pinnacle&#8221;). Developers use the PNaCl toolchain
 to produce a single, portable (<strong>pexe</strong>) module. At runtime, a translator
 built into the browser translates the pexe into native code for the
-relevant client architecture.</p>
-<p>The right side of the diagram shows how to use traditional (non-portable)
-Native Client. Developers use a nacl-gcc based toolchain to produce multiple
+relevant client architecture. Translation occurs before any code is executed.</p>
+<p>The right side of the diagram shows how to use (non-portable) Native Client.
+Developers use a nacl-gcc based toolchain to produce multiple
 architecture-dependent (<strong>nexe</strong>) modules, which are packaged into an
 application. At runtime, the browser decides which nexe to load based
 on the architecture of the client machine.</p>