Meltano

<https://github.com/meltano/meltano/pull/10445?utm_source=github-slack-app&amp;utm_medium=notifications&amp;utm_campaign=notification-title|#10445 docs: document env_specific on plugin settings>
Pull request opened by <https://github.com/lavkushry|lavkushry>
*Summary*

• Document `settings[*].env_specific` in the plugin definition syntax reference.
Fixes <https://github.com/meltano/meltano/issues/3449|#3449>

*Test plan*

• Preview the new settings subsection

*Summary by Sourcery*

Documentation:
• Document the `settings[*].env_specific` plugin setting, including its storage behavior, security considerations, and usage example.
<https://github.com/meltano/meltano|meltano/meltano>