Support additional keywords

[chriswep]

i personally use RADAR quite often - for things that are not actually ToDos (in the "needed for this issue" sense) but rather reminders for later. I personally would find it useful to track those in a separate column on the project board (i added a separate issue related to that here https://github.com/ribtoks/kanboard-tdg-import/issues/3).

I know it's not super difficult to add a keyword in the source and make a new binary. But maybe a command line option to set the keywords would make sense?

[ribtoks]

Hi Chris. Sure, you can add a new flag of type arrayFlags in main.go and change parseToDoTitle() in todogenerator.go. Please don't forget about some tests. Thanks