List backends in README as a table

[hpcfzl]

This PR originates from #678 (reply in thread), where I had reordered all README-listed backends into a table. No contents were otherwise removed, though repetition of demo link, docs link, and "external Markdown files" links was omitted.

Changes:

• Changed backend list into a table
• Applied consistency:
  • Triple backticks become single backticks where possible
  • Asterisks in lists become hyphens
  • Most code-like names become styled in code
  • Double spaces become single spaces
  • Non-titlecase titles become titlecase
  • Zig/zig becomes Zig
  • Dx11 becomes DX11
  • Renamed the new raylib_zig_custom.md file to use dashes:
    • Changed link in README
• Added new titles:
  • Examples Repository
  • Frequently Asked Questions
• Mentioned new group box widget
• Parent bullet points end with a colon, unless they're a title

I ended up avoiding TODO-like lists as advised. In the README, not here.

Opinions are welcome, especially those about:

• The brief descriptions of Standalone, On top, and As app in the table
• Link to #Floating Windows which didn't actually link. I assume it's a Markdown thing
• Anywhere I inserted TODO, which is why this PR is originally being submitted as a draft

I didn't really have all that much to add, but I did notice the lack of mention for WebGL 2 being different from WebGL without mipmaps. Web backend is only referred to as Web backend in README, see last TODO left in README. Could just be me though.

[hpcfzl]

Here's the new view for an easy comparison.

[david-vanderson]

I'm pretty happy with how it looks, after getting the table narrower. Still need to look into those TODO's. I might punt on them though.

Not sure it's worth putting info about webgl2 vs webgl. I think almost everything uses webgl2 now, and anybody who cares knows what they are looking for.

[hpcfzl]

Following your changes:

• I see you caught a few inconsistencies of my own, thanks for the edits
• The vertical | separator was a conscious choice, since Homepage contains all those subsequent links separated by ·:
  • Left as-is for now, but would prefer to revert the change
• Docs having their own section is fine, but as a second level title below Examples would probably be more appropriate?
  • Repeating the link to online docs there might be unnecessary. However, I understand that someone could quickly Ctrl F to that section, missing the top-most link
• The table cell Backend/Purpose was supposed to be one of those diagonally separated cells. The extra text indeed takes up more space, so I suppose leaving only Backend there is fine as well in the case that you insist
• Agreed on the narrower table, zig build is something that probably should be avoided repeating. So I like the idea of having a common example like zig build sdl3-app before the table:
  • I have extended on that, seeking opinions
• Sorry for causing a stir, but I don't think it's evident right away that such a complementary repository, dvui-demo, exists:
  • So now I placed its mention above the table, obviously still open to changes
  • And since the top of Getting Started is related, I added a TODO there
• What's your stance on the bullet points style? Having a consistent style across README or mixed starting capital letters, colons, and so on? Whichever you think is best for the majority of Zig audience, assuming they care in the first place. I sometimes find that the inconsistencies are visually too noisy
• I see that words like Zig and DVUI are also now lowercase zig and dvui, is that your preference?
• Frame rate with a space between frame and rate is more accepted I think, but I'm not so certain about mainloop. I kept them same as here

Completely new changes:

• Small code formatting fix
• About possible new OpenGL and GLFW backend, I have:
  • Inserted a table entry, accompanied by TODOs
  • Mentioned this in the list of backends
• Renamed the new raylib_zig_custom.md file to use dashes and changed its link in README

I'll use the GitHub feature to comment within the actual code next time, as we narrow down the changes necessary.

[david-vanderson]

We are getting to the really small stuff now, so mostly less important than getting this done. Mostly my changes are geared towards people reading quickly.

* The vertical `|` separator was a conscious choice, since `Homepage` contains all those subsequent links separated by `·`:

That makes sense, but visually it looks weird to have them be different.

* Agreed on the narrower table, `zig build` is something that probably should be avoided repeating. So I like the idea of having a common example like `zig build sdl3-app` before the table:
  
  * I have extended on that, seeking opinions

I see where you're coming from, but it's too much text for people just starting out. I want to give them something to immediately run first, then follow up with the table. I'll try to put a link to either the get started part or dvui-demo there.

* What's your stance on the bullet points style? Having a consistent style across README or mixed starting capital letters, colons, and so on? Whichever you think is best for the majority of Zig audience, assuming they care in the first place. I sometimes find that the inconsistencies are visually too noisy

I don't care all that much, but generally less is better (so no colons). Usually I refrain from starting with a capital unless it's a full sentence, or it reads like a title. But again this is very minor.

* I see that words like `Zig` and `DVUI` are also now lowercase `zig` and `dvui`, is that your preference?

I still don't have a good opinion on this. A lot of capitals looks disruptive in a sentence, especially "DVUI". I guess we shoot for lowercase and see how it goes?

I'll make a few followups and then merge it. We can always update stuff later.

[hpcfzl]

No problem, I recognise that you have actual features to fulfill.

Don't forget to remove all the TODOs or comment out the ones which aren't already.

[david-vanderson]

The plural thing was for both SDL and web, so two different backends. Right?

I have on my list to follow this up with:

• updating the screenshot
• copying the example table to the dvui-demo readme
• updating the tables once the new glfw backend is merged

I know we didn't get to all the stuff you wanted, but this is a good improvement. I really appreciate the detailed work here. Thank you!