Add make-input-port, make-output-port to TR
repairs for `srcloc->string`

Fix predicate on argument, including allowing chaperoned srclocs.

Closes PR 14376
readline: fix broken registration of "mzscheme" as name

Maybe it should be "racket", instead, but leaving as "mzscheme"
in case anyone has customizations using that name.
[unsafe-]fl{real,image}-part: fix contracts in docs and errors

Closes PR 14368
Add #:literal-sets for several TR optimizer cases

The matching was too inclusive in some cases, causing
spurious optimizations (or type-table lookup failures).

Closes PR 14380
Rename -no-obj and -no-filter to -empty-obj and -top-filter.
Add -no-obj and -no-filter abbreviations.
Use abbreviations and default values for filters more in unit tests.
Fix doc typo.

Reported by cosmez on IRC.
One more #:literal-sets

Missed this in 07bde5063b5a3a83f61e85f00a1c6ce6e0a097d2
Add more tests for PR 14380

Related to 07bde5063b5a3a83f61e85f00a1c6ce6e0a097d2
Improve Guide section on other editors

Mention racket-mode and replace the `raco planet` mention with
`raco pkg` instead.
pull in Gumby
initial commit
rename
try
more
First attempt at a "learning" section
Add Redex book too for better balance
Forgot Redex cover