doc: add contribution guide in pull request template

Bambooin · Bambooin · commit 14e9b2e551db · 2021-09-12T20:14:15.000+08:00
diff --git a/.github/pull-request-template.md b/.github/pull-request-template.md
@@ -9,6 +9,7 @@ Fixes #
 
 #### Build tasks success
 Successfully running following tasks on local
+- [ ] [CONTRIBUTING](CONTRIBUTING.md)
 - [ ] `./gradlew spotlessCheck`
 - [ ] `./gradlew assembleDebug`
 
