Placing .tex and .svg files in a separate directory

[poldap]

Description

Thank you for the great work!

I wanted to use --file-prefix tikz/ so that all .tex and .svg files were located in a subdirectory and did not clutter the workspace. Although it works for the .tex files, which are placed in the right place, they never get compiled because of os.path.base here. https://github.com/jbn/itikz/blob/e5dc8e07b2da064bfc4a6ea2dc7e32df8ca4b21d/itikz/init.py#L129-L131

What I want to do

I guess I am asking permission to go through the logic and make a PR enabling this use eventually.