`register_value_with_doc` doesn't utilize the doc part

[shenlebantongying]

I was looking at the doc and how the doc are generated.

It appears that various built-in functions are missing in the generated documentation (the book) and the built-in (help indent), such as cons, reverse...

All these are missing, (help cons) doesn't print CONS_DOC

steel/crates/steel-core/src/primitives/lists.rs

Lines 92 to 95 in d81f428

	.register_value_with_doc("cdr", crate::primitives::lists::CDR, CDR_DOC)
	.register_value_with_doc("rest", crate::primitives::lists::REST, REST_DOC)
	.register_value_with_doc("append", crate::primitives::lists::APPEND, APPEND_DOC)
	.register_value_with_doc("reverse", crate::primitives::lists::REVERSE, REVERSE_DOC)

[mattwparas]

Thanks for the report. I looked into it and it's just a bit of an oversight as I changed some of the implementation with doc handling. I'll have a PR today which updates them to be included

[mattwparas]

Should also be fixed in #193 - I just tacked it in there