Change scribble/blueboxes to scribble/signature-box

[jackfirth]

In racket/drracket#291 and racket/drracket#172, it was decided that "signature box" is a much better term than "blue box", and various parts of drracket's documentation were updated to use this phrase. Scribble's scribble/blueboxes library uses the term "blue box" in its documentation and the names of its exported identifiers.

We should add a scribble/signature-box library that's the same as scribble/blueboxes but with changed names. Then we should deprecate the scribble/blueboxes library and point users to the new library.

[spdegabrielle]

@jackfirth I'd suggest this issue should be labelled 'good first issue' as it is a lot of steps but achievable for a beginner.

Steps to complete the task;

1. fork this reporacket/scribble
2. identify files that need to be changed https://github.com/racket/scribble/search?q=blueboxes&unscoped_q=blueboxes
3. create local copy on your PC
4. copy scribble-lib/scribble/blueboxes.rkt to scribble-lib/scribble/signature-box.rkt
5. copy scribble-doc/scribblings/scribble/blueboxes.scrbl to scribble-doc/scribblings/scribble/signature-box.scrbl
6. copy scribble-lib/scribble/valid-blueboxes-info.rkt to scribble-lib/scribble/valid-signature-box-info.rkt
7. change 'bluboxes' to 'signature-box' in files 4 ,5 , 6(above), scribble-doc/scribblings/scribble/internals.scrbl, scribble-lib/scribble/contract-render.rkt & scribble-doc/scribblings/scribble/renderer.scrbl.
8. delete scribble-lib/scribble/blueboxes.rkt, scribble-doc/scribblings/scribble/blueboxes.scrbl & scribble-lib/scribble/valid-blueboxes-info.rkt
9. test (is rebuilding racket/scribble sufficient?)
10. create PR for racket/scribble

[jackfirth]

@spdegabrielle Good idea! I don't seem to have issue-labeling powers though, and I don't know who would.

[jackfirth]

Thank you @rfindler!

[nloadholtes]

Hi, I gave this a PR a try but the tests weren't passing. This is the first time I've tried working with racket so I'm not sure what the error message means. I put the details in the PR #286