Update and consolidate i18n

[imnasnainaec]

This change is 

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.68%. Comparing base (34b59b5) to head (ade06ed).
Report is 9 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3313   +/-   ##
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  Coverage   74.68%   74.68%           
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  Files         280      280           
  Lines       10744    10744           
  Branches     1298     1298           
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  Hits         8024     8024           
  Misses       2354     2354           
  Partials      366      366           

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backend	83.89% <ø> (ø)
frontend	66.67% <ø> (ø)

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[jasonleenaylor]

src/i18n/index.ts line 29 at r2 (raw file):

      detection: { order: ["queryString", "path", "navigator"] },
      supportedLngs: i18nLangs,
      // "languageOnly" will (e.g.) only load 'es' if the browser is 'es-MX'

This comment is confusing to me.
I think it trying to say that the browser will only use the language part of the tag, and not the region - but that isn't what the words are saying.

[jasonleenaylor]

Reviewed 3 of 6 files at r1, 2 of 2 files at r2, all commit messages.
Reviewable status: 5 of 6 files reviewed, all discussions resolved (waiting on @jmgrady)

[jasonleenaylor]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @jmgrady)