add owi c command and examples for all subcommands

[redianthus]

cc @filipeom

[redianthus]

As you can see, I got rid of the Makefile, this allows to build everyting with dune and a small script in OCaml (src/libc/script.ml).

I also moved all the dune-site stuff directly where the files live (for instance we have a src/libc/include/dune now).

I also moved the instrumentor stuff into libc, it is not really related to the libc but let's say this folder is for all C related stuff.

[filipeom]

Suggested change

	["llvm" "clang" "lld" "wabt"] {os-family = "debian"}
	["llvm" "clang" "lld" "wabt"] {os-family = "debian"}
	["llvm" "wabt"] {os-family = "osx"}

CI is failing, and it appears to be because we're not specifying the dependencies here. However, I'm not quite sure if these are the only packages required for macOS. Additionally, I couldn't find mentions of lld or clang in Homebrew packages, so I assume they must be included in llvm.

[redianthus]

Thanks. I added this line directly myself as running dune b owi.opam was needed to generate the new owi.opam file...

Let's see if this is enough 😅

[filipeom]

This appears to have done nothing 😅

I was looking at the os-family available in here and perhaps wrongfully assumed osx would work. Inspecting the CI, it looks like it's looking for os-family = "homebrew"? I have no current way to test this tho, sorry.

...
# Detecting depexts using vars: arch=x86_64, os=macos, os-distribution=homebrew, os-family=homebrew
...

[redianthus]

Well, still not. Let's merge as the CI is green on Linux. We'll fix macOS later.

[filipeom]

At least it's installing wabt and llvm not. But it's still saying opt: command not found

[redianthus]

Yes I saw... @krtab is going to have a look.

[redianthus]

I removed the Quick-start section of the README and wrote a short example of all sub-commands we have. It is much better now IMO.

You can see how it renders on my fork.