Database Relationships Docs

[gewenyu99]

What does this PR do?

This PR accomplishes the following goals:

• Create a shorter getting started page
• Create subpages to discuss more in-depth concepts like permissions, relationships, DB design.
• Create documentation for new relationship concepts.

Proposed Outline

The new documentation will be split into three pages /docs/databases/ Databases -> Getting started, creating simple DB, Indexes (and types), running a list command

• Add nav links to queries, relations, pagination, etc.
• /docs/create-relationships/ Creating relationships, relationship types, performance some examples and suggested use cases. - /docs/consume-relationships/ How to perform CRUD operations on relationships, lots of examples.

Move under own page /docs/queries/ Queries -> Indexes, Queries, lots of examples. Since this is used for all list endpoints, mention that.

Test Plan

Related PRs and Issues

[TBD, we need to update the markdown files in appwrite/appwrite to point to new "Queries" page]

[gewenyu99]

REDACTED

[gewenyu99]

@stnguyen90 @abnegate @christyjacob4 Have another look? Hoping all minor issues now 😬