feat: configurable base branch name (#5)

* feat: configurable base branch name

Accepts a new input, `base_branch_name`, to indicate the name of
the branch containing the README file to be updated. Default
`main`.

* Update action.yml

Co-authored-by: Kevin Heis <[email protected]>

action.yml

@@ -12,6 +12,10 @@ inputs:
     required: true
   branch_name:
     description: "If the learner is working in a branch, add the branch name."
+  base_branch_name:
+    description: "Optional name of the base branch (default: main)."
+    required: false
+    default: "main"
 runs:
   using: composite
   steps:
@@ -41,8 +45,8 @@ runs:
           exit 0
         fi
 
-        echo "Make sure we are on the main branch"
-        git checkout main
+        echo "Make sure we are on the base branch ($BASE_BRANCH_NAME)"
+        git checkout $BASE_BRANCH_NAME
 
         echo "Remove 'open' from any <details> tags"
         sed -i.tmp -r 's/<details id=([0-9X]+) open>/<details id=\1>/g' README.md
@@ -61,7 +65,7 @@ runs:
         echo "Update the STEP file to TO_STEP"
         echo "$TO_STEP" > .github/script/STEP
 
-        echo "Commit the files, and push to main"
+        echo "Commit the files, and push to base branch"
         git config user.name github-actions
         git config user.email [email protected]
         git add README.md
@@ -73,7 +77,7 @@ runs:
         if git show-ref --quiet refs/heads/$BRANCH_NAME
         then
           git checkout $BRANCH_NAME
-          git cherry-pick main
+          git cherry-pick $BASE_BRANCH_NAME
           git push
         else
           echo "Branch $BRANCH_NAME does not exist"