[docs] lack of types conversion and binding docs

[liesauer]

for example

1. how to receive number at rust side
2. how to receive or return object or any complex object

{
    "a": "a",
    "b": [true, 1, {}, []],
}

3. which types are compatible or can be safely transfer
4. it there any suggestion on types conversion, function declaration(the right way to deal with the data)

just like this, CLR vs. PHP types

[simonhyll]

Thank you for the feedback! I'll track this for 2.0, I think this might be good information for us to put in the IPC blog post potentially as well as possibly a blog post about tauri-specta and specifically type/struct handling across the IPC.