POC adding tailwind

[segiddins]

Had to disable the base/preflight stuff because the CSS resets were breaking existing designs. This gives us a blank slate.

[codecov]

Codecov Report

Merging #4113 (cd310b6) into master (885f10e) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4113   +/-   ##
=======================================
  Coverage   98.89%   98.89%           
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  Files         279      279           
  Lines        6317     6317           
=======================================
  Hits         6247     6247           
  Misses         70       70           

[indirect]

Looks reasonable to me, and like a good starting point towards eventually migrating onto newer tools.

[simi]

What's the plan in here? 🤔

[indirect]

My hope is something like:

1. make tailwind available for use (this PR)
2. new UI features can use tailwind for layout and design
3. in the next 1-3 months, engage a designer to work on the planned new gem show page and updated visual design
4. use Tailwind to implement new gem pages and updated visual design
5. remove sass, bourbon, compass, and other older frontend packages

[simi]

@indirect sounds great.

What about to merge this with also new pipeline onboarding like #3470? Would it be possible to move only tailwind part to new pipeline and slowly offboard the old one?

[indirect]

I am happy for the modern pipeline to be either stripped-down sprockets or propshaft—I'm not sure if propshaft has enough bugs worked out yet to work for us, but if it does work for us I am happy to use it. Either way, I don't want to block any PR on another PR, we can merge this and then shift app/build from Sprockets to Propshaft when the Propshaft PR lands. 👍🏻

[indirect]

@segiddins let's resolve the merge conflict and get this one landed before any more conflicts crop up. the future stuff outlined here can happen in the future. 👍🏻

[segiddins]

Rebased

[simi]

🤔 I still do not understand why tailwind is needed. But I'm not going to block this.