Update variable names / future-proofing

[dbox]

I think we tackle this before #192.

Per conversation on zspecza/stylus-conventions#8 (comment)

We need to:

• Add $ to all variables
• Unify all variable names to be $dash-case
• Reference @declandewet's conventions doc in contributing?

[zspecza]

I'm not so certain on the last one 🐔, my conventions doc has gone seriously unmaintained because of my limited time to devote to open source at my current job

[dbox]

FWIW I think the community needs such a doc, but i'm fine to cross off #3.

[dbox]

I have this almost done. It was not trivial. Post update on this soon.

[dbox]

Done in #209

Probably should make this v0.5.x. Not sure if there would be any breaking changes but better safe than sorry.

So up next v0.4.3:

• adds rule()
• adds hover-glow() and hover-float()
• adds click-down(),click-inset(), click-shadow(), & click-shrink()
• moves print to reset

v0.5.0

• new variable structure.

v0.5.1

• select-box()
• ??
• ??

Then we'll push dropping nib to *v0.6.x *

[jescalan]

Good roadmap. I'm going to get some stuff merged today, sorry for the delays!

[dbox]

Honestly I didn't expect the nib removal to go so quickly. Not sure we even really need to have new variable structure be it's own release now. We can just roll it out with the sans-nib update.