Update to crossterm 0.20.0

[EverlastingBugstopper]

When using crossterm 0.20.0 with termimad 0.11.1, I get the following error:

error[E0308]: mismatched types
   --> src/command/output.rs:125:36
    |
125 |                 skin.bold.add_attr(Underlined);
    |                                    ^^^^^^^^^^ expected enum `crossterm::style::types::attribute::Attribute`, found enum `crossterm::style::Attribute`
    |
    = note: perhaps two different versions of crate `crossterm` are being used?

error[E0308]: mismatched types
   --> src/command/output.rs:125:36
    |
125 |                 skin.bold.add_attr(Underlined);
    |                                    ^^^^^^^^^^ expected enum `crossterm::style::types::attribute::Attribute`, found enum `crossterm::style::Attribute`
    |
    = note: perhaps two different versions of crate `crossterm` are being used?

It looks to me as if there were some breaking changes in the crossterm crate that just moved where the types live. termimad should update their API to accept this new type, and possibly consider re-exporting the types that are expected to be used within the skin builder API so consumer crates don't have to worry about matching dependency versions.

[Canop]

I'm not sure about reexporting. When you use termimad, you probably also directly use crossterm.

[EverlastingBugstopper]

Yeah, that part is definitely not necessary to fix this - just a possible path. I only suggest it since the termimad API directly accepts input parameters thats types are not part of this crate. An example of this pattern in the ecosystem is reqwest which re-exports the types from the http crate so you don't have to include it as a dependency.

[Canop]

I also often reexport types in my crates, but mostly when you don't need to use the other types directly. My opinion isn't yet made on this point.

[Canop]

done: versions of Termimad 0.12.x are based on Crossterm 0.20

[EverlastingBugstopper]

Thanks!!