feat: add json5 syntax highlighting to gqlconfig

Author: Kumar Harsh

package.json

@@ -93,6 +93,12 @@
  "GraphQL"
  ],
  "configuration": "./syntaxes/language-configuration.json"
+ },
+ {
+ "id": "json5",
+ "extensions": [
+ ".gqlconfig"
+ ]
  }
  ],
  "grammars": [