Add three columns for code

[todatamining]

column1 --------------------------column2 ------------------------------------------column3
code in commit1..................code in commit2........................................change in commit3

currently, only code in commit2 is shown. It is hard to know what has been changed or changed to exactly.

[pomber]

Not sure about this one. One of the things people like about this tool is that there isn't too much noise.
#63 will add a link to GitHub commit where you can see the diff, maybe that's enough, or maybe we can add a special diff view later.

[shayanb]

I agree. The minimal view is really clear and perfect for finding the diffs. The url to the actual commit can help to investigate the details and change log.

[pomber]

From #22

The current visualization is more for browsing different versions of a file rather than viewing the diff between two versions. I want to keep that, but I agree that people usually want to see a diff after browsing the history.
I'm thinking on adding some way to activate a "diff mode" that animates between diffs, as you change the "left" and/or the "right" version of a file.

[katrinleinweber]

How about only 2 columns? git-temporal does this. Would that be a good compromise between the 2 use-cases?