Please join us!! We want to make Lisp-based languages easier to use.
Simply join the readable-discuss mailing list if you want to join us. You can get up-to-speed via the archives; the mailing list is archived by SourceForge, mail-archive, and Gmane. You might find the following pages helpful:
We love code contributions! Code is maintained in our git repository; see [Workflow] for how we manage the code branches. The easy way to start contributing code is to select the "develop" branch (not the "master" branch) and fork it; when you're done, submit a push request.
Of course, you really need to read the [Solution] and [Tutorial] first to usefully discuss notation issues. If you want to discuss changes to the notation, you really need to read the [Rationale] first.
We want the code to be portable. It's hard to write portable Scheme code. Generally, we stick with R5RS, since most Scheme implementations are not going to implement R6RS. That can be challenging, e.g., R5RS (and before) don't have a module system, nor a simple exception-raising system. R7RS looks very promising, but it's not clear how well it will be accepted.
It's clear that most people realize that LISP's poor syntax is a real problem for use, because people keep working on trying to solve it. A survey of approaches, which mentions "readable", is at LISP Sans Parenthesis, 1958 to 2013, a Survey.