Add note to writingsuggestions that's it's been merged into HTML

[marcoscaceres]

People are still citing the writing suggestions explainer around the place and are getting confused that it's not already in HTML. '

Would you mind adding a note to the Writing Suggestions explainer explaining that it's already in HTML?

[sanketj]

Thanks @marcoscaceres. Apologies that this wasn't done earlier. The explainer is archived now: #805.

[marcoscaceres]

No problem at all. Thanks for the speedy action on it!