fix(docs): clean up npm test docs

[wraithgar]

Adds an example and standardizes the language w/ start and stop

References

Closes npm/statusboard#250

[npm-deploy-user]

found 1 benchmarks with statistically significant performance improvements

• app-large: no-clean:audit

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	42.669 ±2.21	25.768 ±0.15	27.177 ±0.28	25.995 ±1.09	1.928 ±0.01	1.939 ±0.01	1.392 ±0.02	10.076 ±0.05	1.352 ±0.00	3.658 ±0.12
#2462	42.137 ±0.81	25.583 ±0.01	27.194 ±0.76	25.789 ±0.94	1.909 ±0.01	1.942 ±0.00	1.377 ±0.00	10.036 ±0.07	1.370 ±0.00	3.248 ±0.16

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	29.602 ±1.17	18.036 ±0.10	18.659 ±0.77	18.228 ±0.42	1.821 ±0.01	1.838 ±0.01	1.259 ±0.00	6.324 ±0.05	1.287 ±0.01	2.511 ±0.04
#2462	30.513 ±0.84	18.028 ±0.07	19.140 ±0.18	18.082 ±0.25	1.821 ±0.02	1.831 ±0.00	1.291 ±0.00	6.352 ±0.02	1.284 ±0.00	3.116 ±0.59