Document how to update a prototype that is already on GitHub

Related documentation

https://govuk-prototype-kit.herokuapp.com/docs/updating-the-kit

Suggestion

We should consider adding some extra instructions to the update tutorial if the prototype was already on GitHub so that other people who have a local copy of the prototype get the changed files.

Steps to add (draft)

• Branch off the main (or equivalent) branch and pull down the latest changes […]
• Once the update has completed locally, commit the files and open a PR etc., depending on the process that the team working on the prototype follows

Evidence (where applicable)

A user who was updating prototypes that were already on GitHub said that it wasn’t clear that after the update was complete, they needed to commit and push up the changed files.

[EoinShaughnessy]

I closed the PR I’d raised, as we don’t know whether this issue has affected more than one user so far. Maybe one to revisit when we have more evidence it’s causing problems.

[EoinShaughnessy]

@lfdebrux Thanks! I’ll raise a PR shortly.