Remove the WebIDL grammar

This grammar uses the same scope name (source.idl) as our existing IDL
grammar. The wrong scope name was listed in grammars.yml which masked
this problem. https://github.com/andik/IDL-Syntax/pull/2 tracks getting
the grammar to use a different scope name; in the meantime we just won't
highlight these files.

grammars.yml

@@ -63,8 +63,6 @@ https://github.com/alkemist/gradle.tmbundle:
 - source.groovy.gradle
 https://github.com/ambethia/Sublime-Loom:
 - source.loomscript
-https://github.com/andik/IDL-Syntax:
-- source.webidl
 https://github.com/angryant0007/VBDotNetSyntax:
 - source.vbnet
 https://github.com/anunayk/cool-tmbundle:

lib/linguist/languages.yml

@@ -3057,7 +3057,7 @@ WebIDL:
   type: programming
   extensions:
   - .webidl
-  tm_scope: source.webidl
+  tm_scope: none
   ace_mode: text
 
 XC: