FEATURE: Switch for graph with days of week under it

[wakatara]

So, I would personally find this useful for spotting patterns in behaviour. Can you add a switch or similar to output day of week under the graph for that day h log --days... ie. MTWTFSS?

While I love the minimalism of the chart, I realized when I matched it up with certain days of the week that I was having a big drop on a certain day that was stopping me from being productive. Would have been enormously more obvious if I could have visually linked it immediately to the offending day (and this to what was messing things up -- a particular recurring meeting on a day I've realized.).