Meltano

<https://github.com/meltano/meltano/pull/10052|#10052 docs: Add Cloud docs to reference index>
Pull request opened by <https://github.com/ReubenFrankel|ReubenFrankel>
*Description*

SSIA

*Checklist*

• I have read the <https://docs.meltano.com/contribute/merge/|contribution guide>

*Was generative AI tooling used to co-author this PR?*

• Yes (please specify the tool below)

*Related Issues*

• Closes #XXXX

*Summary by Sourcery*

Documentation:
• Introduce a new reference index page that lists key Meltano documentation areas, including command line, settings, plugin syntax, glossary, Cloud, and deprecated UI/API server.
<https://github.com/meltano/meltano|meltano/meltano>

<https://github.com/meltano/meltano/pull/10052|#10052 docs: Add Cloud docs to reference index>
Pull request merged by <https://github.com/ReubenFrankel|ReubenFrankel>
<https://github.com/meltano/meltano|meltano/meltano>