Update lambda-reader.rkt to allow keyword-args

Update lambda-reader.rkt to allow keyword-args, and also more than 10 args, and also allow for skipped args
Update lambda-reader.rkt to fix bug

added (require racket/list ... append*)
Update lambda-reader.rkt to fix bug

added (require (for-syntax racket/base))
Add the examples from PR message as tests.
Indent to stay ~< 80 columns.
DRY `return`
Refactor nested `cond`s to `match`.
Add extra test for using both % and %1
Rename the find-XXX functions.
Add Alex Knauth to THANKS.md
Simplify `parse`: Always make rename transformer.

The rename transformer makes `%` an alias for `%1` (which is a really
smart way to handle this!).

Prior to this commit, `parse` avoided creating the rename transformer in
the case where the function has no arguments at all, IIUC because it
wouldn't be used.

However more generally, `%` won't be used if `body` doesn't
use `%` -- which wasn't being checked for.

If defining the rename transformer when it won't be used, is "wasteful",
we should really check for the general case.

However. If I understand correctly, it's not really "wasteful". So let's
not bother checking at all. Let's simply define it, always.
Update tests.
Document reader function literal enhancements.
Merge branch 'AlexKnauth-master'. Closes #38.

Enhance reader function literals to support keyword arguments and
arbitrary number of arguments.