Divide managing index page

[rsill-neo4j]

Splitting the managing-indexes page, similar to what #1406 does for constraints

Once both are in dev, the pages should also be moved to the schema nav entry.

Most of the files touched here are updated links.
Relevant for Review are the commented out listings for indexes in list-indexes.adoc and drop-indexes.adoc - those were collected from create-indexes.adoc.

[AlexicaWright]

I like the idea of breaking this up, it's much more readable this way. My only comment has nothing to do with the breaking up of the structure but with the admonition syntax.
Will any redirects/page-aliases be needed as a result of this re-org?

[Hunterness]

Did find some odd things on the setup lists (and then some other comments as well)

[neo4j-docops-agent]

This PR includes documentation updates
View the updated docs at https://neo4j-docs-cypher-1432.surge.sh

New pages:

• Create indexes
• Drop indexes

Updated pages:

• Additional Cypher features
• Advanced query tuning example
• Basic query tuning example
• MERGE
• Create, show, and drop constraints
• Search-performance indexes
• The impact of indexes on query performance
• Full-text indexes
• Vector indexes

[Hunterness]

Just one small thing I noticed that doesn't really have to do with the dividing of the pages 🤷

[Hunterness]

In Cypher 5 we return both provider and configuration settings but in Cypher 25 we only return the configuration settings in the options column. So this sentence should maybe be updated to reflect that 🤔 This would also be true for show constraints as well and not just show index (as I assume it has a similar sentence around it's options column).

Not really related to your PR I just noticed this sentence now.