Use rcrc

[adarsh]

Reason for Change

• rcrc manages symlinking much more efficiently than I do.

  Changes

• Add an rcrc to configure rcm excludes and things not to symlink.
• Update the install script to use rcm.

  Minor

• Copy a more recent rubocop.yml just for posterity.

Addresses #21

[adarsh]

Thanks @gfontenot for inspiration.

[gfontenot]

❤️