Fix formatting of code in table in bsn! documentation.

[kpreid]

Objective

Fixes missing content and formatting in the bsn! macro documentation:

Solution

Rustdoc tables https://doc.rust-lang.org/rustdoc/how-to-write-documentation.html#tables are defined as GFM tables https://github.github.com/gfm/#tables-extension- which specifies that

Include a pipe in a cell’s content by escaping it, including inside other inline spans

and so we have to add backslashes even inside a code section.

Also adjusted the alignment of the right edge on some other lines.

Testing

• Viewed the documentation locally.