File associations for "Brewfile"

The `Brewfile` (1) of Homebrew (2) is not detected as Ruby syntax,
therefore a association will be added to map it to the `ruby` syntax
type.

References:
  (1) https://github.com/Homebrew/homebrew-bundle
  (2) https://brew.sh

Resolves GH-186

snowblocks/visual-studio-code/settings.json

@@ -33,6 +33,7 @@
   "extensions.ignoreRecommendations": true,
   "extensions.showRecommendationsOnlyOnDemand": true,
   "files.associations": {
+    "Brewfile": "ruby",
     "*.jsx": "javascriptreact",
     "*.js": "javascript"
   },