Document manual workflow triggering in GitHub Actions

Add comprehensive documentation for manually triggering workflows via
GitHub UI and CLI. Explains the important limitation that the "Run
workflow" button only appears for workflows merged to master, and
provides CLI alternatives for testing workflows before merge.

Includes:
- Step-by-step UI instructions
- GitHub CLI command examples
- List of workflows supporting manual triggers
- Explanation of force_run parameter
- Use cases for manual triggering

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

.github/read-me.md

@@ -105,6 +105,62 @@ Most workflows use minimal permissions. The comment-triggered workflows require:
 - `pull-requests: write` - To post comments and reactions
 - `actions: write` - To trigger other workflows
 
+## Manually Triggering Workflows
+
+Many workflows support manual triggering via `workflow_dispatch`, which allows you to run them on-demand from any branch.
+
+### Using the GitHub UI
+
+**Important**: The "Run workflow" button only appears for workflows that exist on the **default branch (master)**. If you've added or modified a workflow in a feature branch, you won't see the button until the workflow is merged to master.
+
+To manually trigger a workflow in the GitHub UI:
+
+1. Go to the **Actions** tab in the repository
+2. Select the workflow from the left sidebar (e.g., "JS unit tests for Renderer package")
+3. Click the **"Run workflow"** dropdown button (top right)
+4. Select the branch you want to run it on
+5. Configure any input parameters (e.g., `force_run` to bypass change detection)
+6. Click **"Run workflow"**
+
+### Using the GitHub CLI
+
+You can trigger workflows from the command line without waiting for them to be merged to master:
+
+```bash
+# Basic manual trigger on current branch
+gh workflow run package-js-tests.yml
+
+# Trigger on a specific branch (e.g., master)
+gh workflow run package-js-tests.yml --ref master
+
+# Trigger with force_run parameter to bypass change detection
+gh workflow run package-js-tests.yml --ref master -f force_run=true
+
+# List available workflows
+gh workflow list
+
+# View recent workflow runs
+gh run list --workflow=package-js-tests.yml
+```
+
+### Workflows Supporting Manual Triggers
+
+The following workflows can be manually triggered with `workflow_dispatch`:
+
+- **`package-js-tests.yml`** - Accepts `force_run` parameter (boolean) to bypass change detection
+- **`main.yml`** - Accepts `force_run` parameter (boolean) to bypass change detection
+- **`lint-js-and-ruby.yml`** - Accepts `force_run` parameter (boolean) to bypass change detection
+- **`rspec-package-specs.yml`** - Accepts `force_run` parameter (boolean) to bypass change detection
+- **`playwright.yml`** - Can be triggered manually
+- And others - check individual workflow files for `workflow_dispatch` configuration
+
+### Why Use Manual Triggers?
+
+- **Test workflow changes** before merging (via CLI only until merged to master)
+- **Re-run CI on master** without making a new commit
+- **Force full test suite** on a branch using `force_run=true`
+- **Debug CI issues** by running workflows on specific commits
+
 ## Conditional Execution
 
 Many workflows use change detection to skip unnecessary jobs: