Update books

ehuss · ehuss · commit 04427b159d52 · 2019-10-01T19:35:13.000-07:00
diff --git a/src/doc/book b/src/doc/book
@@ -1 +1 @@
-Subproject commit 871416b85c1a73717d65d6f4a9ea29e5aef3db0e
+Subproject commit 04806c80be0f54b1290287e3f85e84bdfc0b6ec7
diff --git a/src/doc/reference b/src/doc/reference
@@ -1 +1 @@
-Subproject commit fa5dfb832ef8a7568e17dabf612f486d641ff4ac
+Subproject commit 320d232b206edecb67489316f71a14e31dbc6c08
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit 67cfbf31df880728dcf7cb35b15b028ec92caf31
+Subproject commit a6288e7407a6c4c19ea29de6d43f40c803883f21
