Copy more doc comments to JS/TS files, unescape comments

[0xd4d]

Closes #2053
Closes #2052

Unescapes comments. Looks like it's coming from proc-macro2, it returns a quoted + escaped string. I couldn't find an unescape function so I had to write it myself.

Copies more comments from rust to js/ts files. I think all comments are copied now.

[alexcrichton]

Thanks for this! I've just got a question about escaping but otherwise looks good to me

[alexcrichton]

I'm personally a bit confused on why we need a method like this, can you help me understand where this is coming from? Where do we acquire an escaped string from, and would it be possible to acquire an unescaped string instead?

[0xd4d]

wasm-bindgen/crates/macro-support/src/parser.rs

Lines 1320 to 1324 in b9f78ab

	TokenTree::Literal(lit) => {
	// this will always return the quoted string, we deal with
	// that in the cli when we read in the comments
	Some(lit.to_string())
	}

That's the code that gets a quoted + escaped string from proc_macro2. I couldn't find an unescape function anywhere. If you know of one, I'll replace this func with that one.

[alexcrichton]

Can the un-quoting/etc happen around there? I don't think it should be happening in the CLI but rather at the source here if possible.

[0xd4d]

It's been moved now. The old code used to unquote the string, but it's also been moved. Let me know if that's considered a breaking change and I'll restore it.

[alexcrichton]

Thanks!