scratch-def features does not include full list

[dschach]

Is your feature request related to a problem? Please describe.
When I add newer features to a config definition (EinsteinGPTForDevelopers, Walkthroughs) I get an error that the string does not match the pattern ^(AddCustomApps:[0-9]+$)

Describe the solution you'd like
Allow all new feature values to be entered without error

Describe alternatives you've considered
n/a

Additional context
Running latest sf version (2.24.4) and latest VSCode extensions

[jlantz]

The script in the repo seems to be parsing the live docs to populate features in the schema. I just hit another one with a client's scratchdef using the new ApexUserModeWithPermset feature that's not in the schema and doesn't appear to be in the docs link the script is parsing:
https://developer.salesforce.com/docs/get_document/atlas.en-us.sfdx_dev.meta