fix(docs): Fix warning: 'end is deprecated, use done instead.'

- There's a warning due to ./node_modules/q-fs@0.1.36 --> node_modules/q@0.8.11
- This may also be due to package.json not being restrictive enough on the q-fs version.
- In any case, q-fs is being retired for q-io/fs, so this fix is probably necssary eventually.