docs: Add notes about developing.

Author: chriswblake

docs/how-to-develop.md

@@ -0,0 +1,29 @@
+# How to Develop
+
+1. Open this project using the dev container config.
+1. Make your changes. Build into the `dist` folder using `npm run bundle`.
+1. Verify all tests run, either in the VS Code test runner or by running
+   `npm test` in the terminal.
+1. Try running using the workflows in the `examples` folder.
+1. Verify the workflows run in `.github/workflows` using the `act` tool.
+   - Check formatting:  
+     `act pull_request -W .github/workflows/linter.yml`
+   - Check the build matches with source:  
+     `act pull_request -W .github/workflows/check-dist.yml`
+   - Check that all tests pass:  
+     `act pull_request -W .github/workflows/ci.yml`
+   - Use CodeQL to check for security vulnerabilities:  
+     `act pull_request -W .github/workflows/codeql-analysis.yml`
+1. Update version in `package.json`.
+1. Merge to `main`. Create a release with same tag as `package.json` version.
+1. Update the major version tag.
+
+## Setup Nektos/Act
+
+```bash
+# .actrc
+--var-file .act.vars
+--secret-file=.act.secrets
+--action-offline-mode
+--container-architecture=linux/amd64
+```