Static R docsite

[ebezzi]

Restores the R static docsite.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 91.36%. Comparing base (b09d336) to head (57bf0ce). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1294 +/- ## ======================================= Coverage 91.36% 91.36% ======================================= Files 82 82 Lines 6482 6482 ======================================= Hits 5922 5922 Misses 560 560 ``` | [Flag](https://app.codecov.io/gh/chanzuckerberg/cellxgene-census/pull/1294/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=chanzuckerberg) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/chanzuckerberg/cellxgene-census/pull/1294/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=chanzuckerberg) | `91.36% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=chanzuckerberg#carryforward-flags-in-the-pull-request-comment) to find out more.

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[ebezzi]

@ebezzi, this looks like an older version of the R docs than what we have up currently.

Should we just grab the R docs from the current gh-pages branch instead?

I used an outdated branch. I pushed an update.