Have nte index use mdix

mdix is a tool to index text files. I'm planning on using this in several
projects so I'm integrating it with nte. This will reduce code duplication
across projects like nte and mgr.
Add simple passthrough for nte search

Search is handled by mdix so we just make sure to give it the right arguments.
Tinker with help docs

Add another example to the docs and a title.
Copy without newline

When we copy the url we do not need or want the final newline character. This
removes that.