Script to add repo to existing monorepo.

Update README.md

Reword.

Switch all references from master to main.

Updating dependencies and Python version.

Break out pushdown_one

Add usage message.

Make build invokable from elsewhere

Linewrap README

Update README.md

Simplify pushdown function.

Change pushdown to find branches in repo.

Fix typo.

Update README.md

Cleaning up Pipfile.