Update runtime files. Add Rust support.
diff --git a/runtime/doc/fold.txt b/runtime/doc/fold.txt
index c3f4132..bdf4a48 100644
--- a/runtime/doc/fold.txt
+++ b/runtime/doc/fold.txt
@@ -1,4 +1,4 @@
-*fold.txt* For Vim version 8.0. Last change: 2016 Jan 02
+*fold.txt* For Vim version 8.0. Last change: 2017 Mar 18
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -79,7 +79,7 @@
:set foldexpr=MyFoldLevel(v:lnum)
This will make a fold out of paragraphs separated by blank lines: >
:set foldexpr=getline(v:lnum)=~'^\\s*$'&&getline(v:lnum+1)=~'\\S'?'<1':1
-this does the same: >
+This does the same: >
:set foldexpr=getline(v:lnum-1)=~'^\\s*$'&&getline(v:lnum)=~'\\S'?'>1':1
Note that backslashes must be used to escape characters that ":set" handles
@@ -203,7 +203,7 @@
1. If a marker with the same fold level is encountered, the previous fold
ends and another fold with the same level starts.
2. If a marker with a higher fold level is found, a nested fold is started.
-3. if a marker with a lower fold level is found, all folds up to and including
+3. If a marker with a lower fold level is found, all folds up to and including
this level end and a fold with the specified level starts.
The number indicates the fold level. A zero cannot be used (a marker with