Colemak-DH keyboard layout updates

[contact_candrew.net]

Summary

Updates to the Colemak-DH keyboard layouts in FreeBSD

• Rename from Colemak Mod-DH (the project name) to Colemak-DH (the layout name)
• Split keyboard layout into the two main variations: Colemak-DH (for ANSI keyboards) and Colemak-DH ISO (for ISO keyboards). The naming is consistent with the XKB implementation.
• Added a few extra symbols for the Compose layer from XKB

For more information, see: https://colemakmods.github.io/mod-dh/keyboards.html

[contact_candrew.net]

I wasn't sure what the 0x symbols in the share/vt/keymaps/*.acc.kbd files meant, so I just kept them with the same keys they were with previously (ie. moved them with the keys).

[contact_candrew.net]

Also, I'm not sure if there is a naming scheme for the keymap files I should be following.

[contact_candrew.net]

@cs I was testing out the revision and found an error:
When I use kbdmap to select Colemak-DH ISO as a keyboard layout, I get the following error:

kbdcontrol: illegal definition line
keymap="colemak-dh-iso.acc.kbd"

I will be busy over the next couple of days, but will investigate this error when I'm free.

[contact_candrew.net]

@cs Sorry about that, the change does actually work fine. It was just an error in how I applied the patch to test it, but thanks for waiting :)