Highlight code changes for a specific timestamp #99
Description
Currently, the timestamps dropdown will "time travel" whenever a new one is selected.
Instead, add a "Time travel" button to trigger that functionality.
And now, whenever a new timestamp is selected, highlight the code lines related to this particular timestamp.
It should probably also have a warning saying that only surviving code done on that moment is highlighted. Code which was modified or deleted later in time will not be shown as this is not a DIFF tool.