Schema explorer

[JulienPeloton]

We should enable an easier exploration of the alert schemas. It is not clear what is available, the meaning of fields, why schemas for real-time & offline (database) are different, etc. This explorer should also expose the LSST alert schema.

• Build a new page. This page should contain 3 tables: ZTF (real-time), ZTF (database), LSST (preview).
• table for each schema should be dynamic (filter on column values)
• If the information exists elsewhere, it should be re-used (to avoid duplicating code)
• there should be an explicit link from the documentation to this page

e.g.

name	type	provenance	description
i:magpsf	float	ZTF	<insert from existing entry>

Actuall, Lasair has a very nice schema browser.