Automated preview instances of iD for tagging PRs

[tyrasd]

Closes #289.
Example of how it will look like: tyrasd#3.

Currently, this has some small limitations:

• Uploading changes is not possible in these test instances, because OSM's Oauth2 setup does not allow wildcard subdomains for the redirect URI. I think that's fine, since these test instances are only meant for testing the tagging PRs, and not intended for editing.
• New strings will now show up when using a locale other than English

To do:

• set secrets to deploy on netlify (NETLIFY_AUTH_TOKEN, NETLIFY_SITE_ID)
• drop action artifacts after deployment

PS: This is very much "inspired" by the implementation made in the openlayers.

[tordans]

New strings will now show up when using a locale other than English

Could you change the preview URL that the bot comments to include ?locale=en (this was the param, right?), so the translation issue is only visible if users force it to?

[tordans]

Also, I assume that openstreetmap/openstreetmap-website#3955 (comment) is a big +1 that this feature is a good idea, right?

[tordans]

This looks great and the PR you linked works as I would expect.

The article I linked at https://github.com/openstreetmap/id-tagging-schema/pull/800/files#r1124938112 had some hints at how to maybe speed up the npm install further with some caching stuff, but I don't know if that would be relevant (enough) for this use case.

This will be a great improvement.

One thing that should likely be part of the PR is an update to the Readme on how to contribute and use this new feature.

[tyrasd]

One thing that should likely be part of the PR is an update to the Readme on how to contribute and use this new feature.

What exactly did you have in mind which should be mentioned in the Readme? As the bot automatically posts a comment directly on each PR, the contributors don't have to do anything manually and the message in the posted comment should be sufficiently "documenting" what it is about?! So, basically I don't know what exactly to put into the readme. ☺️ If you can suggest some lines to be added to the Readme, I'd be very happy to add them, though.