Running `grawkit` locally can be a hassle for one-off tasks, and can be hard to iterate against
when plotting graphs based on complex command-line descriptions. Given recent fixes for POSIX
compatibility, this commit implements a basic web-based "playground"-style application that allows
for entering command-line descriptions in an HTML textarea, and seeing the results (or errors)
instantly.
The playground application itself is built in Go (Awk itself would be insufficient for the
throughput required, but may be investigated in the future), with the excellent GoAwk library
providing parsing and execution duties, therefore making for a pure-Go implementation (other than
Grawkit itself).
Additional support for setting custom styling and an online deployment with Docker are forthcoming.
