Update README.md

https://github.com/Valloric/ycmd/pull/628

README.md

@@ -732,6 +732,7 @@ Quick Feature Summary
 * Go to definition (`GoTo`, `GoToDefinition`, and `GoToDeclaration` are
   identical)
 * Management of `racer` server instance
+* View documentation comments for identifiers (`GetDoc`)
 
 User Guide
 ----------
@@ -1363,7 +1364,7 @@ under the cursor. Depending on the file type, this includes things like:
 * etc.
 
 Supported in filetypes: `c, cpp, objc, objcpp, cs, python, typescript,
-javascript`
+javascript, rust`
 
 #### The `GetDocImprecise` subcommand
 

doc/youcompleteme.txt

@@ -965,6 +965,7 @@ Rust ~
 - Go to definition (|GoTo|, |GoToDefinition|, and |GoToDeclaration| are
   identical)
 - Management of 'racer' server instance
+- View documentation comments for identifiers (|GetDoc|)
 
 ===============================================================================
                                                      *youcompleteme-user-guide*
@@ -1638,7 +1639,7 @@ under the cursor. Depending on the file type, this includes things like:
 - etc.
 
 Supported in filetypes: 'c, cpp, objc, objcpp, cs, python, typescript,
-javascript'
+javascript, rust'
 
 -------------------------------------------------------------------------------
 The *GetDocImprecise* subcommand