Add the option to export the pomodoro information to a csv file

[maikol-solis]

The pomm package (https://github.com/SqrtMinusOne/pomm.el) has the feature to export every started pomodoro to a CSV file.

Replicating the pomm package, the file could have these columns:
— timestamp
— status (stopped, paused or running)
— kind (work, short-break, long-break or nil)
— iteration
— heading under the pomodoro

This could be an excellent feature if we want to make some analytics in Python or R with the data.

Thanks.

[felipelalli]

Good idea!