Make driver projects use a standalone primary navigation, and remove from main TOC

[amotl]

About

This patch makes the primary navigation of all driver projects standalone, so we no longer need to take any TOC assembly concerns into consideration on them, for the benefits of better detanglement. In this spirit, the patch tries another attempt to remove the dedicated driver projects from the main TOC, in order to exclusively make them part of a larger assembly of connectivity options.

Rationale

After CrateDB received PostgreSQL compatibility, it gained a way larger surface of connectivity options, which is a good thing. At the same time, our legacy drivers became less maintained, which is natural. In this spirit, we shouldn't present them any longer on the main stage, but just refer to them within a larger gallery where other more optimal connectivity options exist, mostly through drivers and adapters which are NOT from our pen.

Outlook

This gives us the freedom to shift the focus of proper guidance to the refurbished drivers section which offers more attractive connectivity options / enumerates them within a broader context.

References

• https://github.com/crate/tech-content/issues/124#issuecomment-3738490742
• Remove outmoded database drivers section #686

Status / Preview

Tested on two downstream projects at crate/crate-npgsql#78 (preview) and crate/crate-jdbc#470 (preview). "All database drivers" links back to the section root.

[bmunkholm]

A few thoughts - nothing blocking:

1. Should first TOC be "Documentation" or the name of the driver? Do we even need that level? If we prefer not to have that, as it's not really that useful?, we can use the technique from the guide to have multiple entries in the root.
2. Should we add the two links Community & Support at the left TOC at the bottom?

[amotl]

a) You can easily change or extend everything at your disposal. b) I prefer not to obfuscate too much by using special techniques, as our journey was originally directed towards getting rid of them.