[LPM] Improve docs

1. Remove disclaimer about LPM not having a track record.
2. More consistent line length.
3. Change `targeted_code` to `targeted_function`
4. Improve example for multiple inputs.
5. Fix link.
6. Improve wording.

Change-Id: I8486c544773bbbd17dd12591ed1c602213275d98
Bug: 769578
Reviewed-on: https://chromium-review.googlesource.com/c/1394310
Reviewed-by: Abhishek Arya <[email protected]>
Reviewed-by: Max Moroz <[email protected]>
Commit-Queue: Jonathan Metzman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#619674}
1 file changed