Fork amp-story to 1.0

[newmuis]

With pending breaking changes to the API and the anticipated release, we should increase the major version number of the amp-story extension to 1.0. We will fork the codebase to and deprecate 0.1 when possible.

Game plan:

• Move 0.1 to 1.0 and make 0.1 an alias of 1.0
• Copy 1.0 back to 0.1 and remove the alias
• Launch 1.0
• Provide validator warnings to users using 0.1
• Provide proactive messaging to users using 0.1
• Provide notices in documentation to avoid using 0.1
• Make 0.1 invalid
• Alias 0.1 to 1.0
• Delete 0.1

[newmuis]

See #14237

[ampprojectbot]

This is a high priority issue but it hasn't been updated in awhile. @newmuis Do you have any updates?

[newmuis]

We are very close to the "Launch 1.0" step of this issue. We will communicate that widely when it happens.

After that, the priority of this should probably be lowered to P2, and we will work on the "Deprecate 0.1" phase.