Add color rule for JavaScript and JSX syntax (#235)

* Add color rule for JavaScript and JSX syntax

This adds support for colors embedded in strings in the JavaScript and JSX syntaxes. This greatly helps when developing UI using CSS-in-JS systems such as [Stitches](https://stitches.dev) or [Styled Components](https://styled-components.com). 

Solves #87.

* Remove dangling commas

Author: mstade

color_helper.sublime-settings

@@ -338,6 +338,18 @@
                 "meta.tag.any.html meta.attribute-with-value.style.html"
             ]
         },
+        {
+            "name": "JavaScript/JSX",
+            "base_scopes": [
+                "source.js",
+                "source.jsx"
+            ],
+            "color_class": "css-level-4",
+            "scanning": [
+                // Covers single and double quoted strings, as well as template strings
+                "string.quoted"
+            ]
+        },
         {
             // Setting is experimental, set "enable" to false if false positives are problematic.
             //