Finalize design for Composer header about mapstory

[glynnis]

#725 is related and covers the technical aspects that affect this design story. I posted this diagram there, but posting here too since it'll help with design:

^ Possible states and flows for a story

[glynnis]

I still need to review these with the team so they aren't final yet, but here are the different states I have designed for w/r/t the header:

Autosave Text

Help Text

MapStory Title

[glynnis]

Button states

[glynnis]

Related: #725

[glynnis]

Some notes that I've validated through a conversation with @sarasafavi:

Three story states can be communicated through the UI:

• Draft (not currently published)
• Published/public, with no staged changes
• Published/public, with staged changes that have not been published yet
  • On the backend: make a duplicate of the published one, where the duplicate has a "draft" flag and is not published. When we're ready to publish changes, the duplicate record with the draft=true gets changed to draft=false (and overwrite the record)
  • From this state, a user can revert to the public version that has no staged changes. If they're working on a story that's an original draft, their only option would be to discard the entire draft (since there's no public version to revert to).
  • If there's a public version of a draft that the user is working on, that's an important state to communicate (i.e. they have staged changes they haven't published yet).

[glynnis]

I confirmed with @davisc that Preview Mode will be part of MVP.

[glynnis]

Calling this one done!

[glynnis]

You can also find these screens on InVision here: https://invis.io/PKBXSE1RJ