Added built-in types as well (string, int, etc)

syntaxes/csharp.json

@@ -324,7 +324,7 @@
           "name": "storage.type.var.cs"
         },
         {
-          "match": "[@]\\b(namespace|class|var|event|delegate|add|remove|set|get|value|new|is|as|using|checked|unchecked|typeof|sizeof|nameof|when|override|readonly|stackalloc|from|where|select|group|into|orderby|join|let|on|equals|by|ascending|descending|if|else|while|for|foreach|in|do|return|continue|break|switch|case|default|goto|throw|try|catch|finally|lock|yield|await|internal|public|protected|private|static|const|sealed|abstract|virtual|extern|unsafe|volatile|implicit|explicit|operator|async|partial)\\b",
+          "match": "[@]\\b(namespace|class|var|event|delegate|add|remove|set|get|value|new|is|as|using|checked|unchecked|typeof|sizeof|nameof|when|override|readonly|stackalloc|from|where|select|group|into|orderby|join|let|on|equals|by|ascending|descending|if|else|while|for|foreach|in|do|return|continue|break|switch|case|default|goto|throw|try|catch|finally|lock|yield|await|internal|public|protected|private|static|const|sealed|abstract|virtual|extern|unsafe|volatile|implicit|explicit|operator|async|partial|bool|byte|sbyte|char|decimal|double|float|int|uint|long|ulong|object|short|ushort|string|void|struct|enum|interface)\\b",
           "name": "meta.class.body.cs"
         }
       ]