docs: Add docs for new Vector type support

[marcelomendoncasoares]

Add docs for the Vector type as implemented on Serverpod's PR 3554:

• New supported type reference.
• Filtering/Querying instructions with examples.
• Indexing instructions.
• Upgrading project instructions to enable vector support.

[marcelomendoncasoares]

@SandPod, it seems that the markdown lint is failing for previously existing pages. Do you want me to correct them in this PR or should we review/merge the new ones and fix them separately?

Error: ./docs/07-deployments/02-deploying-to-gce-terraform.md:214:302 MD059/descriptive-link-text Link text should be descriptive [Context: "[here]"]
Error: ./docs/07-deployments/03-deploying-to-gcr-console.md:9:88 MD059/descriptive-link-text Link text should be descriptive [Context: "[here]"]
Error: ./docs/08-upgrading/03-upgrade-to-two.md:65:165 MD059/descriptive-link-text Link text should be descriptive [Context: "[here]"]
Error: ./docs/08-upgrading/04-upgrade-to-two-point-two.md:3:280 MD059/descriptive-link-text Link text should be descriptive [Context: "[here]"]

[SandPod]

All changes look good! I will fix these lint issues on main and will merge update this PR.