Clarification of "Lesson" vs "Episode" in the text

[dvalters]

In the text of some of the episodes, the words lesson and episode are used interchangeably in some places, which led to a bit of confusion for me in preparing for the instructor training. I think it is clear now (Lesson - a whole set of episodes on a core topic i.e. Python, Unix Shell etc.; Episode - each subsection/separate page with a number in the Lesson)

I was going to open a PR with some minor text changes to fix this, if that seems reasonable?

[maxim-belkin]

Absolutely! Please do so, changing one episode per PR.

[maxim-belkin]

Thanks for your pull requests! Have you found any other improper uses of the word lesson?

[dvalters]

Yep - couple more PR's to follow - just a bit caught up with other work today