Update benchmark results in the readme

[sindresorhus]

We just released Chalk 3 with some large performance improvements. This is what I'm seeing with Chalk 3 and Node.js 12:

~/Downloads/ansi-colors/bench master*
❯ node index

# All Colors
  ansi-colors x 150,257 ops/sec ±0.95% (90 runs sampled)
  chalk x 490,982 ops/sec ±0.48% (94 runs sampled)

# Chained colors
  ansi-colors x 20,122 ops/sec ±0.55% (92 runs sampled)
  chalk x 412,857 ops/sec ±1.12% (92 runs sampled)

# Nested colors
  ansi-colors x 52,308 ops/sec ±0.49% (91 runs sampled)
  chalk x 93,588 ops/sec ±0.26% (92 runs sampled)

Would be great if you could re-run the benchmark on your machine and update the readme.

[doowb]

Thanks for the issue and congrats on those performance improvements!

We've been working on some changes here and we'll make sure to update the benchmarks when we push those up.