Update mdbook
diff --git a/Cargo.lock b/Cargo.lock
index 2233162..50380a4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -617,7 +617,7 @@
  "clippy_utils",
  "if_chain",
  "itertools 0.10.1",
- "pulldown-cmark 0.8.0",
+ "pulldown-cmark",
  "quine-mc_cluskey",
  "regex-syntax",
  "rustc-semver",
@@ -2124,9 +2124,9 @@
 
 [[package]]
 name = "mdbook"
-version = "0.4.12"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0651782b4cc514c3f98c0acf9b5af1101a735bbe1ac6852bb1a90cb91bdf0ed4"
+checksum = "f6e77253c46a90eb7e96b2807201dab941a4db5ea05eca5aaaf7027395f352b3"
 dependencies = [
  "ammonia",
  "anyhow",
@@ -2138,8 +2138,8 @@
  "lazy_static",
  "log",
  "memchr",
- "open",
- "pulldown-cmark 0.7.2",
+ "opener",
+ "pulldown-cmark",
  "regex",
  "serde",
  "serde_derive",
@@ -2147,6 +2147,7 @@
  "shlex",
  "tempfile",
  "toml",
+ "topological-sort",
 ]
 
 [[package]]
@@ -2375,15 +2376,6 @@
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
 [[package]]
-name = "open"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c283bf0114efea9e42f1a60edea9859e8c47528eae09d01df4b29c1e489cc48"
-dependencies = [
- "winapi",
-]
-
-[[package]]
 name = "opener"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2796,23 +2788,12 @@
 
 [[package]]
 name = "pulldown-cmark"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca36dea94d187597e104a5c8e4b07576a8a45aa5db48a65e12940d3eb7461f55"
-dependencies = [
- "bitflags",
- "getopts",
- "memchr",
- "unicase",
-]
-
-[[package]]
-name = "pulldown-cmark"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ffade02495f22453cd593159ea2f59827aae7f53fa8323f756799b670881dcf8"
 dependencies = [
  "bitflags",
+ "getopts",
  "memchr",
  "unicase",
 ]
@@ -4616,7 +4597,7 @@
  "expect-test",
  "itertools 0.9.0",
  "minifier",
- "pulldown-cmark 0.8.0",
+ "pulldown-cmark",
  "rayon",
  "regex",
  "rustdoc-json-types",
@@ -5394,6 +5375,12 @@
 ]
 
 [[package]]
+name = "topological-sort"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa7c7f42dea4b1b99439786f5633aeb9c14c1b53f75e282803c2ec2ad545873c"
+
+[[package]]
 name = "tower-service"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/src/tools/rustbook/Cargo.toml b/src/tools/rustbook/Cargo.toml
index de1327d..b8c67de 100644
--- a/src/tools/rustbook/Cargo.toml
+++ b/src/tools/rustbook/Cargo.toml
@@ -9,6 +9,6 @@
 env_logger = "0.7.1"
 
 [dependencies.mdbook]
-version = "0.4.12"
+version = "0.4.14"
 default-features = false
 features = ["search"]