[git] alias for creating GitHub Pages branches

Need an alias (in either the shell or Git itself) to automatically [follow the steps to manually create project pages](http://help.github.com/pages/#project_pages_with_the_automatic_page_generator) from a local clone.

Read the linked GitHub Pages automatic page generator instructions first, then inspect the repository's existing shell and Git alias conventions. Define the alias around the manual project-pages steps and verify it works from a local clone, including that the expected Pages branch is created.

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