[doc] Add back heading to index.md

diff --git a/src/doc/index.md b/src/doc/index.md
index cf3f36b585e38a2523a8c4b2bf99ea93d0fdce33..c85a6e33b85c6d1429f7f8246afbd99e5e3eb86d 100644 (file)
--- a/src/doc/index.md
+++ b/src/doc/index.md
@@ -1,5 +1,7 @@
 % Cargo, Rust’s Package Manager
 
+# Installing
+
 ### Install Stable Rust and Cargo
 
 The easiest way to get Cargo is to get the current stable release of [Rust] by