Enforce linebreak style in js source code

Author: GuillaumeGomez

src/librustdoc/html/static/.eslintrc.js

@@ -21,6 +21,10 @@ module.exports = {
             "error",
             "double"
         ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
         "no-var": ["error"],
         "prefer-const": ["error"],
         "prefer-arrow-callback": ["error"],