Incorporate proper readme and architecture docs about firefox-translations

[kpu]

In light of #55 (thanks), I want the UI people to be trying the outbound translation feature. Is there a document aimed at a technical windows user who doesn't have npm on how to use the very latest extension? Steps like get nightly, edit stuff in about:config, install XPI. It seems the XPI is built on tags https://github.com/mozilla/firefox-translations/actions/workflows/publish_artifact.yml

[andrenatal]

Every commit builds and artifact, so one could:

1 - Download the artifact from here https://github.com/mozilla/firefox-translations/actions/runs/1818968414. It will be downloaded as a zip
2 - In Nightly, type about:addons click on the gear, then install from a file and load the saved zip file.
3 - On about:config change extensions.translations.disabled to true; extensions.experiments.enabled to true; javascript.options.wasm_simd_wormhole to true

This should be enough.

[kpu]

Add xpinstall.signatures.required to false since that job isn't signing then it worked. Can we add a README section?

[andrenatal]

Feel free.

[andrenatal]

I just filed an issue here: #89

[eu9ene]

I have a draft of the Sequence diagram for message flow on paper. It helps a lot to understand communication between components. We can use something like https://mermaid-js.github.io/mermaid/#/ or https://github.com/plantuml/plantuml with simple text notation to make it editable.