CI/fmt: enforce exact line width, not just less than that.

[kianenigma]

Not sure if this is feasible, so opening it as a discussion rather than an issue.

Perhaps I am the only one annoyed by line width in comments, but I think even with max_width and others, we see code comments in substrate like:

/// A function that returns                                  | (100)
/// some value based on rabtirary                            |
/// length of this comment that still passes formatting check|
/// as long 
/// as it is less than 100 in width
fn foo() {} 

and I find that very irritating to the eye when reading code.

I personally use https://marketplace.visualstudio.com/items?itemName=stkb.rewrap to make sure comments that I write are perfectly aligned with the 100 max width.

Does anyone know a tool such that we can apply this to the whole codebase, and ideally maintain it?