[BUG] Multiple H1s generated on platform landing pages

[djwfyi]

Describe the bug
The docs landing page for each platform results in two titles.

source/index.rst already has a title.
Then we are including /source/includes/|platform|/quickstart.rst and each of the platform quickstarts ALSO has a title.
We need to remove the extra title from the quickstart.rst files for each platform.

See, for example, https://min.io/docs/minio/windows/index.html.

The first H1 comes from /source/index.rst.
The second H1 comes from /source/includes/windows/quickstart.rst

See https://github.com/miniohq/min.io/issues/2714 for more context.

[djwfyi]

Note that this isn't just the Windows quickstart include, but all of the platform includes need to be fixed.

[djwfyi]

Will probably need to move the .. container:: directive for each quickstart to a conditional at the top of the index.rst page.