Meltano

<https://github.com/meltano/sdk/pull/3533|#3533 docs: Added `NumberType` to reference index page>
Pull request opened by <https://github.com/edgarrmondragon|edgarrmondragon>
SSIA

*Summary by Sourcery*

Documentation:
• Adjust reference index documentation entries, including NumberType.
<https://github.com/meltano/sdk|meltano/sdk>

<https://github.com/meltano/sdk/pull/3533|#3533 docs: Added `NumberType` to reference index page>
Pull request merged by <https://github.com/edgarrmondragon|edgarrmondragon>
<https://github.com/meltano/sdk|meltano/sdk>