Provide validation schema for .luarc.json

Eliminates the need for $schema key in most cases

Author: Cassolette

.vscodeignore

@@ -19,6 +19,7 @@
 
 !images/logo.png
 
+!setting
 !syntaxes
 !package.json
 !README.md

package.json

@@ -1577,6 +1577,12 @@
                 }
             }
         ],
+        "jsonValidation": [
+            {
+                "fileMatch": ".luarc.json",
+                "url": "./setting/schema.json"
+            }
+        ],
         "semanticTokenScopes": [
             {
                 "language": "lua",