docs: 完善API文档

[codecov-io]

Codecov Report

Merging #34 into master will decrease coverage by 5.02%. The diff coverage is n/a.

@@            Coverage Diff            @@
##           master     #34      +/-   ##
=========================================
- Coverage   73.82%   68.8%   -5.03%     
=========================================
  Files          28      20       -8     
  Lines         875     779      -96     
  Branches      173     191      +18     
=========================================
- Hits          646     536     -110     
- Misses        229     243      +14

Impacted Files	Coverage Δ
packages/fie-report/lib/retcode/request-node.js	37.5% <0%> (-62.5%)	:arrow_down:
packages/fie-report/lib/retcode/conf-node.js	20% <0%> (-40%)	:arrow_down:
packages/fie-report/lib/retcode/sampling.js	40% <0%> (-20%)	:arrow_down:
packages/fie-report/lib/retcode/apis.js	20.28% <0%> (-8.7%)	:arrow_down:
packages/fie-task/lib/run.js	85.33% <0%> (-1.63%)	:arrow_down:
packages/fie-fs/lib/rewrite-file.js	92.3% <0%> (ø)	:arrow_up:
packages/fie-fs/lib/copy-directory.js	81.81% <0%> (ø)	:arrow_up:
packages/fie-home/lib/index.js
packages/fie-log/lib/index.js
packages/fie-npm/lib/index.js
... and 12 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update e47b973...1534691. Read the comment docs.