Documentation and language server file generation

[makspll]

Given we have function and type metadata available via traits and the various registries, we should generate a lanugage agnostic "binding" content format, which can then be transpilled to things like:

• Documentation
• Language server definition files

Tasks:

• Fill in gaps in the function metadata storage and traits #246
• Design & Write language agnostic bindings format #247
• Write backends for documentation and lua language server formats #248

[makspll]

The format should support:

• fields
• functions
• types

Each type should be expressed together with stable type ID's, the "wrapper" types like Val Ref and Mut, names for fields and function arguments should be forwarded, and generic documentation strings too.

The types should also export as much information from the type registry as necessary