Document docs workflow

Author: spawnia

CONTRIBUTING.md

@@ -10,7 +10,7 @@ For smaller contributions just use this workflow:
 
 - Fork the project.
 - Add your features and or bug fixes.
-- Add tests. Tests are important for us.
+- Add tests to ensure your changes work and will continue working.
 - Check your changes using `composer check`.
 - Add an entry to the [Changelog's Unreleased section](CHANGELOG.md#unreleased).
 - Send a pull request.
@@ -134,6 +134,9 @@ composer bench
 
 We document this library by rendering the Markdown files in [docs](docs) with [MkDocs](https://www.mkdocs.org).
 
+> You may propose changes to the docs via merge requests against the `master` branch.
+> Do not edit the generated HTML files in the `gh-pages` branch directly, they are automatically generated.
+
 Generate the class reference docs:
 
 ```sh

Makefile

@@ -5,6 +5,9 @@ it: fix stan test docs ## Run the commonly used targets
 help: ## Displays this list of targets with descriptions
 	@grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(firstword $(MAKEFILE_LIST)) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[32m%-30s\033[0m %s\n", $$1, $$2}'
 
+.PHONY: setup
+setup: vendor ## Set up the project
+
 .PHONY: fix
 fix: rector php-cs-fixer ## Automatic code fixes