specify files & remove wrong main of package.json

Author: MoOx

package.json

@@ -2,7 +2,6 @@
   "name": "cssrecipes-grid",
   "version": "0.4.0",
   "description": "BEMish grid component",
-  "main": "index.js",
   "keywords": [
     "browser",
     "style",
@@ -24,6 +23,12 @@
   "bugs": {
     "url": "https://github.com/cssrecipes/grid/issues"
   },
+  "files": [
+    "CHANGELOG.md",
+    "LICENSE",
+    "lib",
+    "index.css"
+  ],
   "devDependencies": {
     "cssnext": "^0.4.0"
   },