Add Keystone Jacks

[spuder]

Allow user to add modules like keystone jacks.

Supposedly there are openscad libraries for this.

[spuder]

https://patents.google.com/patent/US5624274

https://imgur.com/j1QgKzW

https://www.reddit.com/r/3Dprinting/comments/5kztlv/comment/dbs426i/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

https://www.printables.com/model/19001-wallmounted-keystone/files

[spuder]

Pushed to branch keystones

TODO:

• Fix hard coded transponse values
• Set minimum height