* chore: remove unused and deprecated properties:
- Remove unused apis key.
- Remove deprecated styleguide property, replace with root-level plugins and extends.
* chore: pass api-docs path to the custom plugin:
- Pass pwd of the calling script as process.env.API_DOCS_ROOT_PATH to plugins to help resolve custom content files.
- Remove lint execution because the exit code always results in execution of the next elif condition.
* chore: simplify api-docs custom content:
- move content overrides from api-docs/openapi/content to api-docs/[version]/content.
- fix version and version numbers in links.
- update cloud and v2.6 from openapi repo.
- move content.js module to docs-content.js and docs-plugin.js.
- revert decorator functions back to taking content as a data argument.
- remove unused servers.yml definition.
Co-authored-by: Scott Anderson <sanderson@users.noreply.github.com>