line breaks

[Chris Holmes]

What do people think of doing hard line breaks? It will make diffs easier, see like https://github.com/tschaub/gpkg-tiles/commit/298972f12017422fa41bb3deed2fd884ae126e47#commitcomment-2992794 - it's hard to see the changes on the really long lines.

Markdown will just treat them as the same line if you don't do a full line break I'm pretty sure. 

The downside is that people then have to do some work to maintain the line breaks. Though I think it's also fine if we're not super strict on that, since most views it doesn't matter. But we could at least start the document with like 100 character line formatting, and it's ok if it goes out from there.