Synced Linear issues should have an `Issue Attachment` to the related Github issue

[janbaykara]

I'm not exactly sure how, but Linear's github import tool and synclinear.com both manage to append these nice, official "Github issue" links to the bottom of the Linear issue description:

By comparison, this tool only adds the link inside the rich text description. Whilst this is functionally fine, it's not quite as slick. The affordance of the button and consistent UI will make the UX this tool provides a bit nicer.

[janbaykara]

OK, the way they do this is by adding an Issue Attachment via the API, to the relevant Github URL and with some nice labelling. This is pretty neat and linear-sync.com could definitely employ the method.

I think it'd be nice if we had the same situation as the screenshot above, so:

attachmentCreate(input:{
    issueId: "<LINEAR_ISSUE_ID>",
    title: "Github Issue <GITHUB_ISSUE_ID>",
    subtitle: "Synchronised",
    url: "<GITHUB_ISSUE_URL>",
    iconUrl: "https://exception.com/assets/icon.png"
    metadata: { issueId: "<GITHUB_ISSUE_ID>", repoID: "<GITHUB_REPO_ID>", teamID: "<GITHUB_TEAM_ID>", etc. }
  })

https://developers.linear.app/docs/graphql/attachments