Move entry to src/index

Our webpack/babel configs require the src/ structure for source files

package.json

@@ -2,7 +2,7 @@
   "name": "scratch-render-fonts",
   "version": "1.0.0",
   "description": "",
-  "main": "./fonts.js",
+  "main": "./src/index.js",
   "author": "Massachusetts Institute of Technology",
   "repository": {
     "type": "git",

webpack.config.js

@@ -5,7 +5,7 @@ const base = {
     mode: process.env.NODE_ENV === 'production' ? 'production' : 'development',
     devtool: 'cheap-module-source-map',
     entry: {
-        'scratch-render-fonts': './fonts.js'
+        'scratch-render-fonts': './src/index.js'
     },
     module: {
         rules: [{