Highlight new Refined GitHub features in dashboard

[fregante]

Continuing from #637

Refined GitHub could use GitHub's dashboard broadcasts/notifications to highlight our own recent big changes and features (and implemented as a reusable package)

[hkdobrev]

I like how OctoLinker does a GitHub release full of info and emoji and then they open it when the extension updates to a new minor version.

[fregante]

I like this implementation: https://github.com/vitalets/github-trending-repos

• Create locked+closed issue
• Manually add comments whenever some worthwhile feature is added
• Open page when users install it, prompting them to follow if they want. Old users will get a one-time tab as well.

This requires very little coding/maintenance. Just open the tab on install, remember this event in chrome.storage, then just update the thread whenever.

[sindresorhus]

Sounds good :)

[fregante]

Done. Checkout the next two references.

Collaborators can add comments as needed, but knowing that everyone will be notified.

The comment can probably just be exactly what we add to readme.md (the markdown link as is) plus the PR, perhaps. Low effort.

- [Show issue resolution in header (was it closed by a PR?)](https://user-images.githubusercontent.com/1402241/35973522-5c00acb6-0d08-11e8-89ca-03071de15c6f.png)
- [Adds links to the default branch and to the latest semver release](https://user-images.githubusercontent.com/1402241/36961980-389bd2b0-2080-11e8-8bff-bb8af52e7128.png)

[fregante]

However, we probably need to just update the second comment or else the latest info will be at the bottom. Perhaps:

1. Copy the previous comment's content
2. Create new comment with the updates
3. Append the previous comment's content
4. Delete the previous comment

This way we get the notifications and we keep the discussion to 2 comments.

[sindresorhus]

@bfred-it Or we can just reverse the comment order in RG ;)

[sindresorhus]

Or hide all comments except for the last one (newest).

[fregante]

Sure. Code vs manual work. 😃

We can collapse the old ones but we should still delete them at that point otherwise the page will become too long.