ci: Add workflow for YAML lint

Add new workflow to `yamllint` compositional skills.

This will be replaced by a smarter version that checks the
qna.yml schema.

Signed-off-by: Christian Kadner <ckadner@us.ibm.com>

.github/workflows/lint.yml

@@ -0,0 +1,35 @@
+# Copyright The InstructLab Authors, 2024
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Lint
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main 
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Checkout"
+        uses: actions/checkout@v4
+
+      - name: "Run YAML linter"
+        run: |
+          yamllint -d "{extends: relaxed, rules: {line-length: {max: 120}}, yaml-files: ['qna.yaml']}" ./compositional_skills/