Markdown style guide: break long text lines or not?

It is unclear to me (and I couldn't find it specified in https://playbook.datopian.com/style-guide/markdown/) whether our style guide for markdown requires, or allows, or prohibits breaking long text lines at a certain maximal length (e.g. 80 chars as is the standard in some places).

Example:

This is the paragraph above in markdown without line breaking:

It is unclear to me (and I couldn't find it specified in https://playbook.datopian.com/style-guide/markdown/) whether our style guide for markdown requires, or allows, or prohibits breaking long text lines at a certain maximal length (e.g. 80 chars as is the standard in some places). 

This is the same paragraph with manual line breaking at 80 characters max:

It is unclear to me (and I couldn't find it specified in
https://playbook.datopian.com/style-guide/markdown/) whether our style guide for
markdown requires, or allows, or prohibits breaking long text lines at a certain
maximal length (e.g. 80 chars as is the standard in some places).

This is the same paragraph with manual line breaking at 80 characters, while allowing overflows for URLs:

It is unclear to me (and I couldn't find it specified in https://playbook.datopian.com/style-guide/markdown/) 
whether our style guide for markdown requires, or allows, or prohibits breaking 
long text lines at a certain maximal length (e.g. 80 chars as is the standard in 
some places).

I noticed that @rufuspollock edited some of my markdown files and removed line breaks, which I tend to insert when writing stand-alone markdown (e.g. README.md files), so I was wondering if this is a rule.

My take is that stand-alone markdown files should have long text lines broken at either 80 or 120 characters. The reasoning being that markdown is meant to be a format that is rendered to HTML or otherwise (e.g. when viewed by Gitlab / Github), but also human readable as-is, for example in an IDE / simple text editor / vim / cat on the terminal. That is the whole point of markdown. When we do not break lines, it becomes much harder to read markdown in some editors. It costs nothing to break and shouldn't hinder anything AFAIK, but for me it means I need to look at the rendered version when reading, and can't just open it in my IDE.