Improve doc generation

[appetrosyan]

Right now the documentation is only generated for configuration parameters, and done very inefficiently.

It's possible to generate the docs as we do right now using cargo doc which would avoid having to compile and link the entirety of Iroha, just to generate the documentation.

[e-ivkov]

I think the best way is to publish static website with GitHub Pages for docs for dev branch. For releases we will just publish the crate with cargo publish then the docs will be automatically available at docs.rs

[0x009922]

Related:

• [suggestion] Enhance configuration reference format #3507