Implementing PartialEq for Ast

[begleynk]

I'm writing a program that needs to translate the comrak AST into a different AST, that a WYSIWYG editor (prosemirror) understands, and back again. I was about to write some tests for this translation, but I found that the Ast struct doesn't implement PartialEq:

error[E0369]: binary operation `==` cannot be applied to type `Ast`
   --> src/prosemirror.rs:105:9
    |
105 |         assert_eq!(*expected_comrak.data.borrow(), *actual_comrak.data.borrow());
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         Ast
    |         Ast
    |
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

Maybe there is there a reason for this that I'm missing? If not, would you consider a pull request that adds this? Would be happy to contribute the change.

I did notice there is a same_node function on Node but it seems this is for checking if two nodes point to literally the same data.

PS. Thanks for maintaining this library!

[kivikakk]

I'd be totally happy to accept such a PR!