/file: split `read.js` & `write.js`

[mindrones]

to ease navigation we could have split there files by output type:

• read.js

  • read/dsv.js
  • read/exportedJs.js
  • read/object.js
  • read/yaml.js

• write.js

  • write/dsv.js
  • write/exportedJs.js
  • write/object.js
  • write/yaml.js