[PLAY-1018] Update kit generator

[markdoeswork]

What does this PR do? A clear and concise description with your runway ticket url

Runway: https://nitro.powerhrg.com/runway/backlog_items/PLAY-1018

Updates the generator so that you can specify swift as a kit type

Had to make some updates to the generator not just to add swift but how we store kits in the menu.yml has changed.
Also added alphabetization logic to the playbook.scss file

Screenshots: Screenshots to visualize your addition/change

How to test? Steps to confirm the desired behavior:

1. git clone playbook
2. cd playbook/playbook
3. bin/rails g kit button (creates a button kit for rails, swift, react)
4. You get a kit for each type
   --
5. bin/rails g kit button --swift
6. generates the kit for just swift
   --
7. bin/rails g kit button --swift --rails
8. generates the kit for swift and rails
9. All two combinations work

Checklist:

• LABELS Add a label: enhancement, bug, improvement, new kit, deprecated, or breaking. See Changelog & Labels for details.
• DEPLOY I have added the milano label to show I'm ready for a review.
• [😈] TESTS I have added test coverage to my code.