Update Colcon-Tutorial.rst

[M61ss]

clarification

[clalancette]

Personally I think this is very subjective; the sentence as-is is correct, and I don't find that this change improves the readability. Because of that, I'm inclined not to take this.

But I'll leave it open for a little while longer to see if one of the other maintainers disagrees.

[christophebedard]

Personally, I'm a fan of using a comma in this case, although the "then" is just extra. I would vote in favour of this change, but I understand that this is kind of opening the door to a ton of tiny, sometime subjective (depending on grammatical preferences, and sometimes native languages) changes like this one.

[fujitatomoya]

i am okay to take this 😃

[M61ss]

I can remove the "then" as I agree that it sounds heavy. The reason of my pull request is that reading the documentation I found difficult to understand the period, I had to read it many times. I am not a motherlanguage, but I am pretty sure that condition and consequence should be separated by a comma to be more readable. Sincerely, I added the "then" because it was embarrassing for me to open a pull request only for a comma.
Anyway, I didn't want to open a controversy about a comma. Feel free to do whatever you want with this doc, I only provided my opinion.

[christophebedard]

It's not really controversial. This kind of change may just not be seen as "critical" enough for some people, and, given that there are a lot more sentences like this, it would be a bit of work if we were to change all of them. However, you're obviously only proposing this one change, so I think it's fine.

It does indeed sound a bit weird to me as someone who is not a native English speaker and instead speaks a language that tends to use commas a lot more than the English language does. So again I'd vote to take this.

[M61ss]

Ok, thank you for your suggestion.