contributor: set specific version

.github/workflows/contributors.yml

@@ -4,13 +4,13 @@ on:
   push:
     branches:
       - main
-
+  workflow_dispatch:
 jobs:
   add-contributors:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: BobAnkh/add-contributors@master
+      - uses: BobAnkh/add-contributors@v0.2.2
         with:
           CONTRIBUTOR: "## Contributors"
           COLUMN_PER_ROW: "6"