Markdown files should end with a newline

[xhujerr]

Expected Behavior

Markdown files end with a newline.

Actual Behavior

Markdown files do not end with a newline. The markdownlint flags this as an issue. Steps to Reproduce

pdoc3 -o docs myscript.py

Look at any of the markdown files generated and see there's no newline at the end.

Additional info

pdoc --version
pdoc 0.11.6

This is very similar to issue #419