Add aliases for single color names (ie red)

[vilmibm]

No description provided.

[modgethanc]

looks like this was fixed in #112, but as an arbitrary personal spelling preference request, i'd also like additional aliases so that 'grey' works in place of everywhere 'gray' is used. so have 'light grey' and 'dark grey' etc.

(this gets me everywhere else that uses standard color names, my fingers just really want to type grey 🙃)

[benjaminwil]

I will pick up what's left of this issue and write tests!

[benjaminwil]

I just submitted a pull request, #128, that explicitly adds a grey alias.

However, I think I would like to expand the scope of what can be aliased (not just colors). This is described in more detail in the PR description.

[modgethanc]

@benjaminwil thanks for that PR! i think it makes sense to have a fairly wide scope of what can be aliased; maybe as part of client settings, there should be room for users to define their own aliases.

this probably warrants a new issue, if you'd like to start one :)