Update star.md

[soerenwolfers]

Solves #4002 and #4004

Also:

• Remove discussion of count(*) from the star expression page -- I don't think they're related in any way, and I think the no-star count() aggregate is better and less confusing anyway.
• Remove the leading list of examples. The page was already unwieldy, and with the new additions it'd just have been a mess
• Restructure the page a bit with the goal to first discuss all SELECT * <MODIFIER> variants and then basically discuss the COLUMNS expression as a super-powered version of that.
• Update the railroad to describe an optional choice between EXCLUDE/RENAME/REPLACE/(LIKE/SIMILAR TO/GLOB) modifiers. Note that previously, this offered a sequence of [optional-EXCLUDE and optional-REPLACE], but now the permitted combinations are a bit odd: no combination works EXCEPT for EXCLUDE + <ANYOTHER> (actually, RENAME + LIKE works but produces a wrong result, I'll open a ticket about that). Therefore, I made the railroad diagram look like no combination is allowed, which I think makes sense until the support has been sanitized. Also, note that COLUMNS(* LIKE/SIMILARTO/GLOB) is not supported but the diagram will look like it is because it offers the same star-options for both branches, same to how it is described in text. I think this should simply be supported rather than painstakingly editing the docs to list this special behavior.

I don't know how to preview the diagram changes (github.dev doesn't help), let me know if there is an easy way!

[szarnyasg]

Thanks for the changes!

I don't know how to preview the diagram changes (github.dev doesn't help), let me know if there is an easy way!

You have to build locally. There's a Docker image for it but it is slow and the JS gets cached easily – I had open a private browsing session to see the new railroad diagram:

It looks great!

The reason I'm parking this for a few days is because this is a v1.2 change. I'll try to set up a subpage for the nightly version, so we can proceed with merging these.