Add Zig highlighting

Closes #1370

.gitmodules

@@ -70,3 +70,6 @@
 [submodule "sublime/syntaxes/extra/sublime-clojure"]
 	path = sublime/syntaxes/extra/sublime-clojure
 	url = https://github.com/tonsky/sublime-clojure.git
+[submodule "sublime/syntaxes/extra/sublime-zig-language"]
+	path = sublime/syntaxes/extra/sublime-zig-language
+	url = https://github.com/ziglang/sublime-zig-language.git

CONTRIBUTING.md

@@ -35,7 +35,7 @@ Tools > Developer > New Syntax from ... and put it at the root of `sublime_synta
 You can also add a submodule to the repository of the wanted syntax:
 
 ```bash
-$ cd sublime/syntaxes
+$ cd sublime/syntaxes/extra
 $ git submodule add https://github.com/elm-community/SublimeElmLanguageSupport
 ```
 

docs/content/documentation/content/syntax-highlighting.md

@@ -35,6 +35,7 @@ Here is a full list of supported languages and their short names:
 - C -> ["c", "h"]
 - C# -> ["cs", "csx"]
 - C++ -> ["C", "c++", "cc", "cp", "cpp", "cxx", "h", "h++", "hh", "hpp", "hxx", "inl", "ipp"]
+- Clojure -> ["clj", "cljc", "cljs", "edn"]
 - ClojureC -> ["boot", "clj", "cljc", "cljs", "cljx"]
 - CMake -> ["CMakeLists.txt", "cmake"]
 - CMake C Header -> ["h.in"]
@@ -143,6 +144,7 @@ Here is a full list of supported languages and their short names:
 - VimL -> ["vim"]
 - XML -> ["dtml", "opml", "rng", "rss", "svg", "tld", "xml", "xsd", "xslt"]
 - YAML -> ["sublime-syntax", "yaml", "yml"]
+- Zig -> ["zig"]
 ```
 
 Note: due to some issues with the JavaScript syntax, the TypeScript syntax will be used instead.

sublime/syntaxes/extra/sublime-zig-language

@@ -0,0 +1 @@
+Subproject commit 9d2083815742ed703b07a25ad3573bec1214d554