fix(docs): clean up npm token docs

[wraithgar]

grammar fixes, notes on authentication tokens, match usage
output with readme

References

Closes npm/statusboard#251

[npm-deploy-user]

found 2 benchmarks with statistically significant performance improvements

• app-medium: cache-only, cache-only:legacy-peer-deps

timing results

app-large	clean	lock-only	cache-only	cache-only legacy-peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@7	47.990 ±0.29	28.690 ±0.17	30.900 ±1.08	28.453 ±0.35	2.196 ±0.01	2.212 ±0.00	1.534 ±0.00	11.192 ±0.04	1.554 ±0.00	3.670 ±0.04
#2482	46.015 ±1.35	27.426 ±0.70	30.349 ±0.53	27.117 ±0.18	2.169 ±0.02	2.178 ±0.00	1.529 ±0.00	10.988 ±0.15	1.518 ±0.00	4.195 ±0.82

app-medium	clean	lock-only	cache-only	cache-only legacy-peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@7	32.624 ±0.05	19.347 ±0.00	21.775 ±0.42	19.894 ±0.09	2.005 ±0.03	2.077 ±0.10	1.392 ±0.02	6.992 ±0.16	1.415 ±0.01	2.884 ±0.16
#2482	32.551 ±1.84	19.863 ±0.36	18.935 ±1.47	17.499 ±0.43	2.058 ±0.03	1.991 ±0.00	1.402 ±0.02	6.911 ±0.03	1.393 ±0.00	2.715 ±0.12