[CI] Add merge_main_to_develop lane (#529)

Author: testableapple

fastlane/Fastfile

@@ -116,6 +116,19 @@ lane :merge_release_to_main do
                "https://github.com/#{github_repo}/actions/workflows/publish-release.yml")
 end
 
+lane :merge_main_to_develop do
+  if is_ci
+    sh('git reset --hard')
+  else
+    ensure_git_status_clean
+  end
+
+  sh('git checkout main && git pull')
+  sh('git checkout develop && git pull')
+  sh('git merge main')
+  sh('git push')
+end
+
 private_lane :appstore_api_key do
   @appstore_api_key ||= app_store_connect_api_key(
     key_id: 'MT3PRT8TB7',