actions: add an example for workflow-dispatch

/repos/{owner}/{repo}/actions/workflows/{workflowname}/dispatches

* fails if the required inputs are not provided
* sets defaults to inputs that are not provided

The type of inputs are only used for building the web UI interface,
not for validation. All values are strings.

actions/example-workflow-dispatch/.forgejo/workflows/test.yml

@@ -0,0 +1,57 @@
+on:
+  workflow_dispatch:
+    inputs:
+      logLevel:
+        description: 'Log Level'
+        required: true
+        default: 'warning'
+        type: choice
+        options:
+        - info
+        - warning
+        - debug
+      tags:
+        description: 'Test scenario tags'
+        required: false
+        type: boolean
+      boolean_default_true:
+        description: 'Test scenario tags'
+        required: true
+        type: boolean
+        default: true
+      boolean_default_false:
+        description: 'Test scenario tags'
+        required: false
+        type: boolean
+        default: false
+      number1_default:
+        description: 'Number w. default'
+        default: '100'
+        type: number
+      number2:
+        description: 'Number w/o. default'
+        type: number
+      string1_default:
+        description: 'String w. default'
+        default: 'Hello world'
+        type: string
+      string2:
+        description: 'String w/o. default'
+        required: true
+        type: string
+
+jobs:
+  test:
+    runs-on: docker
+    container:
+      image: code.forgejo.org/oci/debian:bookworm
+      options: "--volume /srv/example:/srv/example"
+
+    steps:
+      - name: save and display context
+        run: |
+          d=/srv/example/workflow-dispatch/contexts/$GITHUB_EVENT_NAME
+          mkdir -p $d
+          tee $d/github <<'EOF'
+          ${{ toJSON(github) }}
+          EOF