Start times on schedule page at 00:00 for consistency with other lessons

[kschwenzfeier]

Improve consistency on scheduling page with other core lessons

Both python lessons within core curriculum show an example schedule starting at 9:00 while all other lessons start at 0:00. I suggest to shift the start to 0:00 as well as it is easier to plan with a "time spent" kind of timescale than a fixed "this lesson starts in the morning and if it doesn't, there will be math involved."

[vahtras]

That makes sense to me

[alee]

This is essentially a duplicate of #571 and will be fixed soon by adjusting https://github.com/swcarpentry/python-novice-gapminder/blob/81690d2c5794a89b287bbc834a1c3a9a74201967/_config.yml#L63

Thanks for bringing it up!