parsimmon: Benchmarking breakdown

Parsimmon is pretty fast, but we’re not sure which parts are fast and which parts are slow!

Add a benchmark folder with examples we can run and some kind of analysis (flame chart?) of where Parsimmon is slow.

We could use these results to make performance improvements to Parsimmon.

About this issue

I guess we could check performance of the current version against the previous version? Do you think that seems reasonable?

You may want to have a look here as a template to start with: https://github.com/SAP/chevrotain/tree/master/benchmark_web

Points of interest:

Running the benchmark the browser is better as:
- Can easily check on different runtimes.
- Can easily use profiling tools in the browsers.
  - I know its possible from node.js too, but did not work as well for me.
I normally use the benchmarks after each new feature has been implemented By comparing Dev version performance to the previous version performance regressions can be avoided…
This benchmark uses both iframes and webworkers in an attempt to isolate the bench cases.
- ~~Not sure if profiling works with webworkers…~~ (it works)