## Summary
Closes#20565.
The Twenty docs package still pointed contributors at the removed
`mintlify build` command. This switches the docs workflow to a
`validate` command, which matches the supported Mintlify CLI command for
validating the documentation build, and updates the README wording to
match.
## Changes
- Replaced the `twenty-docs` package `build` script with a `validate`
script.
- Renamed the Nx docs target from `build` to `validate` and kept it
wired to `mintlify validate`.
- Updated the README validation command to `npx nx run
twenty-docs:validate`.
## Verification
```bash
$ npx -y mintlify validate --help
usage: mintlify validate [options]
Options:
-t, --telemetry Enable or disable anonymous usage telemetry [boolean]
--groups Mock user groups for validation [array]
--disable-openapi Disable OpenAPI file generation
[boolean] [default: false]
-h, --help Show help [boolean]
-v, --version Show version number [boolean]
Examples:
mintlify validate validate the build
```
```bash
$ npx -y mintlify build
Unknown command: build
```
I also started `npx -y mintlify validate --disable-openapi`; the CLI
recognized the command and began validating, but this Windows
environment could not finish Mintlify framework extraction because it
hit an EPERM symlink error inside the local `.mintlify` cache.
