Update docs building and actions

[abhro]

• Use newer Documenter
• Use GitHub Actions to deploy docs
• Fix doctests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.45%. Comparing base (91eeb42) to head (72cf164).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #233   +/-   ##
=======================================
  Coverage   89.45%   89.45%           
=======================================
  Files           7        7           
  Lines         673      673           
=======================================
  Hits          602      602           
  Misses         71       71           

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[oxinabox]

I am kinda surprised this package is still working.
Since most newer work is on DimensionalData.jl
or perhaps KeyedArrays.jl or one of the others.

But still this PR looks sound.
And having the docs work is good.

Ping me to merge this if i forget to once CI is passing

[abhro]

Unit tests fail on newest Julia v1 (1.12.4) :/
The most recent commit on main (91eeb42) also seems to fail on those tests. The logs for that are expired, though, so I can't tell if it's failing in the same manner

[abhro]

The test failure is on combine(), which this PR doesn't change. Should this be considered good to merge?
@oxinabox