closes https://linear.app/tryghost/issue/MOM-170
When the subtitle field is included in the editor it creates a disconnect with post revisions if the underlying custom excerpt data is not included so we'd like to both preview and restore the subtitle when the in-editor subtitle field is enabled.
- added `post_revisions.custom_excerpt` column to schema
- added migration to add `post_revisions.custom_excerpt` to existing databases
- added migration to populate `post_revisions.custom_excerpt` with the current `post.custom_excerpt` value from the associated record
- ensures no data is inadvertently lost when restoring an old version
- using current data matches what would have happened previously where custom_excerpt was never overwritten when restoring an old version
- updated post revisions handling to accept the `custom_excerpt` field
- updated Admin's revision preview and restoration to display and set the `custom_excerpt` field
refs https://github.com/TryGhost/DevOps/issues/50
- we should default to keeping the rule on and so I've excluded lines
that currently use `any` to avoid the need to go and fix them all up
This is an initial start to using TypeScript in our non-core Ghost packages.
- Adds a prepare script to build the project after installing deps
- Adds an initial tsconfig.json which is compatible with our node env
- Migrates all of the code to TypeScript, including tests
- Updates tests to use ts-node so that we don't need to compile the tests
- ts-node is installed at the top level because the env is weird with lerna and
doesn't work otherwise
- Updates the yarn dev script to build the project with the --all and --revisions flag
