[WIP] Export project to Gist

[magland]

Adds functionality for saving a project to Gist. This includes #97 content, so that should get merged first.

To try it out, click on "Export" and then there's a button "Export to GitHub Gist". It will walk you through the steps and provide instructions on providing an access token with proper scope.

In a separate PR we can figure out what to do about updating an existing gist.

To summarize:

• Export
• Export to GitHub Gist
• Read instructions on getting the PAT
• Enter the PAT
• Click "Export to GitHub Gist"
• Retrieve the url to the gist AND the shareable SP url that loads the gist

[magland]

As discussed previously, I think this PAT method is the best way forward for saving gists... rather than making a GH app and using oauth. If we allow saving to GH repo in the future, we'll want to make a proper GH app.

[magland]

I think there should be an distinction between "export" and "save". Export to a zip, save to a gist. So I'm going to make this two separate buttons on the left panel and we'll see how this looks.

[WardBrian]

I think there should be an distinction between "export" and "save". Export to a zip, save to a gist. So I'm going to make this two separate buttons on the left panel and we'll see how this looks.

I think I agree, but I would personally swap the names, with save meaning to the local file system, and export meaning to another service (gist)

[magland]

Replaced by #114