feat: add get-repo-name (#20)

Reviewed-on: #20
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

get-repo-name/action.yaml

@@ -0,0 +1,16 @@
+name: Get repo name
+description: Outputs the repository name without the owner (e.g. "owner/repo" → "repo")
+
+outputs:
+  name:
+    description: The repository name without the owner
+    value: ${{ steps.repo-name.outputs.name }}
+
+runs:
+  using: "composite"
+  steps:
+    - id: repo-name
+      shell: bash
+      run: |
+        REPO="${GITEA_REPOSITORY:-$GITHUB_REPOSITORY}"
+        echo "name=${REPO##*/}" >> $GITHUB_OUTPUT