Summarise approach and decisions for internationalisation in the Design System backlog

[vanitabarrett]

What

Write up a summary of our final approach for internationalisation and why we decided to follow that approach. Might also be a good opportunity to talk about the other things we tried and explain why those don't work. Also anything we've decided not to do (e.g: because it's not part of our MVP solution; because it's out of scope).

Why

We should try and be transparent about the decisions we make, to help people understand why we've done things a certain way. This may also help as somewhere to refer people to if we get questions on support.

Who needs to work on this

Content, Developer

Who needs to review this

Content, Developer

Done when

• [ ] On Github, add backlog comment in backlog, e.g https://github.com/alphagov/govuk-design-system-backlog/issues/99
• [ ] For follow-up, prepare responses to support questions?