Here, let's create quick reference documents for Perl 6.

For simplicity, use only plain text. That eases creation of tables, and makes
sure nothing needs to be escaped. Assume 80 characters width. Headings begin in
the 1st column, everything else is 4-space indented.

Think of this as a small booklet, a pocket reference.

This is the place to describe syntax rather than semantics. It's a huge
perlcheat-like document.

Alphabetically sorted:

- control      # looping / topicalizing constructs (while, given, if, etc)
- data         # data types (scalars, arrays, hashes, pairs, ...)
- func         # list of functions with their arguments
- mod          # modules
- namespace    # namespaces
- oo           # object orientation
- op           # operators
- reduction    # reduce metaoperator
- rules        # rules
- smartmatch   # smart matching operator
- sub          # subroutine signatures and calling
- unicode      # how to enter Unicode in various editors
- var          # special variables