imba: border aliases missing

I’ll be updating this in the next alpha (in a few hours). Don’t have a system in place for deprecations etc just yet, and since we’re still in alpha I’ll just brutally change them 😛 So if you are using them in your project now you might need to search around and update.

Will also push new version of vscode plugin to fix autocompletion for them etc.

As a consequence of moving border aliases into bd prefix, we can also use bs for box-shadow. I think it feels pretty consistent with bg:gray2 br:2px bs:glow - same length for all these common shorthands, and everything starting with b is related to appearance of the box.