Add Data.Text.show and Data.Text.Lazy.show

[Lysxia]

Closes #183

[Bodigrim]

Awesome!

[andreasabel]

Maybe this should have been in 2.2 rather 2.1.2.
Formally it is ok with PVP to add a new function in a minor bump.
However, since show is in Prelude, everyone importing Data.Text unqualified will get breakage.
So maybe 2.2 would have been wiser...

• https://codeberg.org/valpackett/http-link-header/issues/1

[Bodigrim]

It's abundantly obvious that importing Data.Text unqualified is unwise, because there dozens of clashes with Prelude, be it with show or without it.

Even in a hindsight, making it 2.2 would not save us any work: since http-link-header has no upper bounds at all, you'd still have to revise it... plus hundreds of innocent packages with text < 2.2 atop of it.

[andreasabel]

Yeah, I guess that's right.