fix(docs): clean up npm shrinkwrap docs

[wraithgar]

Just a small spelling fix and some width reformatting.

References

Closes npm/statusboard#244

[npm-deploy-user]

no statistically significant performance changes detected

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	41.388 ±1.13	25.804 ±0.17	26.620 ±0.00	24.206 ±0.49	1.915 ±0.02	1.923 ±0.00	1.354 ±0.02	10.048 ±0.01	1.392 ±0.00	3.098 ±0.04
#2488	42.352 ±1.95	25.496 ±0.15	25.378 ±0.06	23.479 ±0.25	1.909 ±0.00	1.898 ±0.00	1.356 ±0.01	10.004 ±0.05	1.356 ±0.00	3.122 ±0.04

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	29.233 ±0.94	17.877 ±0.06	17.056 ±0.35	16.550 ±0.04	1.821 ±0.03	1.818 ±0.01	1.259 ±0.00	6.338 ±0.07	1.297 ±0.01	2.979 ±0.67
#2488	29.884 ±1.20	18.337 ±0.04	17.771 ±0.70	16.979 ±0.32	1.804 ±0.00	1.807 ±0.00	1.268 ±0.01	6.323 ±0.00	1.279 ±0.02	2.306 ±0.08

[wraithgar]

This file is cleaned up in #2475