updated links to main repo

Author: ThatAmuzak

package.json

@@ -9,10 +9,10 @@
  "email": "hasanbayat1393@gmail.com"
  },
  "scopedRegistries": [],
- "changelogUrl": "https://github.com/ThatAmuzak/UnitySingleton/blob/convert-to-upm/CHANGELOG.md",
+ "changelogUrl": "https://github.com/UnityCommunity/UnitySingleton/blob/main/CHANGELOG.md",
  "license": "MIT",
- "licensesUrl": "https://github.com/ThatAmuzak/UnitySingleton/blob/convert-to-upm/LICENSE",
- "documentationUrl": "https://github.com/ThatAmuzak/UnitySingleton/blob/convert-to-upm/README.md",
+ "licensesUrl": "https://github.com/UnityCommunity/UnitySingleton/blob/main/LICENSE",
+ "documentationUrl": "https://github.com/UnityCommunity/UnitySingleton/blob/main/README.md",
  "samples": [
  {
  "displayName": "Samples",