Create branch if it does not exist

Author: jdbaldry

.github/workflows/update-make-docs.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Update procedure
         run: |
           BRANCH="update-make-docs"
-          git checkout "${BRANCH}"
+          git checkout -b "${BRANCH}"
           curl -s -Lo docs/docs.mk https://raw.githubusercontent.com/grafana/writers-toolkit/main/docs/docs.mk
           curl -s -Lo docs/make-docs https://raw.githubusercontent.com/grafana/writers-toolkit/main/docs/make-docs
           if git diff --exit-code; then exit 0; fi