Add "else" to the list of gn keyword

Add "else" as a valid keyword for gn syntax highlighting for
editor that uses TextMate syntax highlighting rules.

Bug: none
Change-Id: Ib63a61457e88fbc35d6091efea6cffdce5211653
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/11161
Commit-Queue: Brett Wilson <brettw@chromium.org>
Reviewed-by: Brett Wilson <brettw@chromium.org>

misc/tm/GN.tmLanguage

diff --git a/misc/tm/GN.tmLanguage b/misc/tm/GN.tmLanguage
index 8be5f56..7ce3a5c 100644
--- a/misc/tm/GN.tmLanguage
+++ b/misc/tm/GN.tmLanguage
@@ -15,7 +15,7 @@
       <key>comment</key>
       <string>keywords</string>
       <key>match</key>
-      <string>\b(?:if)\b</string>
+      <string>\b(?:if|else)\b</string>
       <key>name</key>
       <string>keyword.control.gn</string>
     </dict>