First of all, you're allowed to post the whole thing as-is, all in the same question. 13,000 characters is well within the limit of what a post may contain (65,536 characters as a hard limit), leaving plenty of room for a project description. A description should ideally contain:
- what problem does your project solve
- what prompted you to write
- what are your current gripes with it
This usually takes a couple thousand characters at most, so you probably won't go over 20k. Just to point out we've seen big posts before and you're no way close to breaking any records. We can handle it.
The benefits to posting as-is are that it's:
- easier for you (less preparation required)
- easier on the reviewer if they want to run the code themselves (again, less preparation)
- easier on anyone else trying to get a piece of it to work in their own project
It's also the most accurate representation of your current code and project. We can't point out you've missed a couple of includes or added includes you're not or no longer using if we can't see which you have where. We also can't help you restructuring your includes if you all pile them together.
On Code Review, we like context. Context tells us a lot about the code, the project, the developer and the problems it may have. Strip away the context and you're actually making it harder on us.
I think all of these (and there are probably more) good reasons not to do what you suggest, outweighing the benefits of the alternative. Keep it as-is, please. I understand the sentiment and on Stack Overflow they'd probably agree with you, but we're a little different.