Update factors-of-flow.md

Some interesting stuff here!  Added a lot of commas, a few hyphens, got rid of some words that seemed redundant, and fixed a few phrases that sounded clunky.  You're also eventually going to have to answer me about the localization, or else I'm going to be changing all your "realise" and "behaviours" to Americanized spellings.  Either way is valid, it's just dependent on what audience you want to reach.  Other things:

Line 9: The block quote for Line 5 was fine, but if the quote actually continues your sentence like in Line 9, it should just be in quotation marks.

Lines 25 - 43: I shifted the contents of this section so that the bullets were together with the supporting paragraphs, since it took me a couple read-throughs to see how you're tying the aspects of the autotelic personality to the personality of programmers.

Line 27: There's got to be a more scholarly way of referencing an XKCD strip than "it has been drawn in stick figures".  Let me think about that one.

Line 43: Unless you go into how other groups don't exhibit these characteristics, I think your concluding statement here ("This would suggest flow is much more prevalent amongst programmers than in other groups of people") is weak.  Can we say "This starts to show how flow is important to the way programmers think and function, and why they work at night."?

Line 63: The layman doesn't know that choosing variable names is not very complicated, and may miss the point you're making.  I added some clarification that this is a simple task, which if you fail, could be a sign of fatigue.

Line 71: Don't think American audiences will understand the Irish stereotype; consider removing.

Line 93: I had to look this phrase up because I'd never heard it before.  Apparently it's Slovenian in origin.  So you could say something like "As they say in my country, habit is an iron shirt" or "There's an old Slovenian proverb: habit is an iron shirt" to give it more context for foreign audiences.  Whatever sounds natural to you.

Line 103:  Changed "mum" to "parents". My dad forced me to do way more chores than my mom did.  :P

Line 109:  Whe you say "pressure piling from the outside", I really wanted to see some examples.  Are you talking about other projects?  Life stuff?

Line 155:  This seems contradictory, because you're saying it has limitations, which makes it sound *NOT* sustainable.  Might help to define exactly how sustainable the "good" flow is.  A week? A month? Until the end of the project?  Indefinitely, with a week vacation now and then to recharge?

Line 190: "Euphamism" didn't seem like the right word here.

Line 200:  I get what you're saying with "glass palace", but the more popular metaphor over here about "glass houses" is more about how they're transparent rather than fragile, and I thought that was a little confusing.  I changed it here to "house of cards", which seems to better reflect what you're saying about building something that can be easily toppled down.

Line 234:  Lawyers are probably more programmers than you think. They don't bill in 15 minute increments because they think or work effectively in 15 minute increments.  15 minutes is basically an "interruption" for them, like a client phone call.  When they're working on a case or reviewing a contract, they do have to hold a program-like system in their heads to be effective at their jobs.  So I didn't feel this comparison was valid.

Line 236: This didn't feel like a very good conclusion.  The fact is, nobody likes to be interrupted when they're concentrating, and ending with a command ("never do this") just makes programmers sound self-important.  I reworded your conclusion a little to reinforce that there is a high risk that you can undo all their work by interrupting them at the wrong time.