[Issue #2498] update some docs

[doug-s-nava]

Summary

Fixes #2498

Time to review: 15 mins

Changes proposed

Bringing frontend and README docs up to date (plus a few updates for typos, formatting, etc.)

Note that internationalization file was largely copy pasted from the Nava platform

Context for reviewers

Test steps

1. probably good to just load up the newly edited files and read them, rather than trying to make sense of the diff
2. VERIFY: all information is correct and presented in a digestable way without leaving out anything important

Additional information

Screenshots, GIF demos, code examples or output to help show the changes working as expected.