[doc] core libfuncs - implement the page skeleton

[remybar]

parent task: #25

Implement the structure of the core libfuncs documentation page.

[remybar]

@mazurroman could you assign this task to me ?

[mazurroman]

@remybar where do you intend to put the content to? On evm.codes it lives on the homepage, but they also only have Solidity & Opcodes.

In Cairo, things are more complicated as we have:

1. The VM with 4 (only!) opcodes (still TBD to document that in the cairovm.codes app)
2. CASM with it's own intricacies
3. Sierra with libfuncs

We could:

1. Show all of that on the homepage with separate headings
2. Have dedicated links on the header to separate subpage

For now I suggest to go with 1 and see where that goes. If the page becomes too busy we can split into subpages. Let me know what you think.

[remybar]

@remybar where do you intend to put the content to? On evm.codes it lives on the homepage, but they also only have Solidity & Opcodes.

In Cairo, things are more complicated as we have:

1. The VM with 4 (only!) opcodes (still TBD to document that in the cairovm.codes app)

2. CASM with it's own intricacies

3. Sierra with libfuncs

We could:

1. Show all of that on the homepage with separate headings

2. Have dedicated links on the header to separate subpage

For now I suggest to go with 1 and see where that goes. If the page becomes too busy we can split into subpages. Let me know what you think.

I would prefer the option 1 as they are different topics (VM, CASM and Sierra) and the Sierra libfuncs table will be quite huge, and I would use the playground as the homepage. But It's up to you !

[mazurroman]

@remybar let's go with your suggestion. We can always update later