Use consistent line endings in all source code files

[trichoplax]

Describe the bug Currently the source code files use a mixture of \n (Linux style) and \r\n (Windows style), which causes confusing diffs when committing changes in git. For example, when editing a Windows style file on Linux, some IDEs will change all the line endings in the file, resulting in the whole file being treated as changed when committing to git.

Expected behavior Ideally we would settle on one style and apply it to all files, including markdown files.

[ArtOfCode-]

We'll standardise on Linux-style line endings. Not something I'm immediately going to go through every file and change, but if someone wants to then feel free.