Document which version the crate targets

[jassielof]

Would help to know what version the crate is using as reference.

By version, I mean the BibLaTeX and Biber version, as BibLaTeX comes to be the specification, and Biber the main reference for implementation.

[YDX-2147483647]

Note that I added the following lines in #102. (I didn't know what you mean by crate at that time.)
They'll need an edit when resolving this issue.

biblatex/src/mechanics.rs

Lines 16 to 18 in 27875ec

	/// References:
	/// - BibTeX: [3.1 Entry Types — BibTeXing (`btxdoc.pdf`, 1988-02-08) | CTAN](https://mirrors.ctan.org/biblio/bibtex/base/btxdoc.pdf)
	/// - BibLaTeX: [2.1 Entry Types — The `biblatex` Package (`biblatex.pdf`, v3.21, 2025-07-10) | CTAN](https://mirrors.ctan.org/macros/latex/contrib/biblatex/doc/biblatex.pdf#subsection.2.1)

However, these lines refer to only entry types. I didn't check how Entry::verify handles the fields.

[jassielof]

Yeah sorry I forgot to be specific about it, I tried to mention it to Laurenz in my PR, and I'll see what he thinks about it to modify it there already. Thanks.