fix sheets example given Sheets API change

pin xlsx version

Merge pull request #8 from cyberdelia/optionally-optional

Allow to pass write options

Merge pull request #7 from adblanc/feat/writeJSON-arguments

add all JSON.stringify args to writeJSON function

Merge pull request #5 from githubocto/aw/xlsx-types

duplicate types for sheetjs

Detail API for each function

Add text library helpers

Fix csvWrite helper function which did not write strings anymore

Fix csvWrite helper function which did not write strings anymore

Simplify the csv examples API by forcing to returna and write object …

…arrays