Rename package-json-schema.json to package.schema.json

Closes GH-119.

Reviewed-by: JounQin <admin@1stg.me>
Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>
Reviewed-by: Titus Wormer <tituswormer@gmail.com>

Author: remcohaszing

package.json

@@ -111,7 +111,7 @@
       },
       {
         "fileMatch": "package.json",
-        "url": "./package-json-schema.json"
+        "url": "./package.schema.json"
       }
     ],
     "languages": [

package-json-schema.json package.schema.json

@@ -1,5 +1,4 @@
 {
-  "$schema": "https://json-schema.org/draft-04/schema",
   "properties": {
     "remarkConfig": {
       "description": "remark configuration",