Update books

ehuss · ehuss · commit 4281fe03ee6e · 2020-03-02T10:00:05.000-08:00
diff --git a/src/doc/embedded-book b/src/doc/embedded-book
@@ -1 +1 @@
-Subproject commit b2e1092bf67bd4d7686c4553f186edbb7f5f92db
+Subproject commit b81ffb7a6f4c5aaed92786e770e99db116aa4ebd
diff --git a/src/doc/nomicon b/src/doc/nomicon
@@ -1 +1 @@
-Subproject commit 3e6e1001dc6e095dbd5c88005e80969f60e384e1
+Subproject commit 71241f403091e021842ca8275740e44d0ab0ece1
diff --git a/src/doc/reference b/src/doc/reference
@@ -1 +1 @@
-Subproject commit 64239df6d173562b9deb4f012e4c3e6e960c4754
+Subproject commit 559e09caa9661043744cf7af7bd88432d966f743
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit 32facd5522ddbbf37baf01e4e4b6562bc55c071a
+Subproject commit db57f899ea2a56a544c8d280cbf033438666273d
