Create way to mark/fix incorrect locations

[olivierbouwman]

Think of a way where people can mark locations as incorrect and propose a new location.
Consider the following:

• Currently there's no database or server aside from a json file and static files. I would prefer keeping things that way.
• Perhaps people can click on the correct place on the map to move a misplaced location to. Ask people to only take post text into consideration as to not locate things the post author didn't want located.
• Perhaps someone can propose a correction and at least 1 other person has to approve before it's permanent?
• If needed consider using some third-party service to store proposed changes before they make it into the data file (Google Sheets/Forms?)
• What kind of abuse can we expect and how shall we deal with it?
  • Perhaps have a setting that can show/hide user submitted corrections.
  • Have a way to undo correction from a certain date range (remove from Google Form responses, revert datafile on github)

Current plan

• Use Google Forms API to take location change submissions (it's free and can handle 5 million records).
• Use Github Actions to periodically (hourly?) pull form submissions.
• Process those form submissions and either mark items as "no location" or with the new proposed location. We probably always want to keep the original location as well, at least for now. Commit updated json file.
• Alterations show up for people.

UX

• Add link to each pin that says “fix location”.
• A message appears with instructions:

Locations have been determined automatically based on the post text and sometimes it's wrong. You correction will help make this map better for everyone, thank you. Any changes you make will appear for everyone in about an hour.
For Hidden Portland posts only: Please base the correct location on the post text only. The original author might have desired a level of privacy and we need to respect that. Thank you.

• Button: No location can be determined from the post text and this items should be removed from the map.
• Button: Pick a new location
  • Adds a draggable pin. When you click on the pin, it shows “are you sure this is the correct new location?” Yes sends in location to Forms API, thanks for submission. No says "please move the pin to the correct location".

[olivierbouwman]

• Allow removal of marker from map (if there's no location in the post text)