[Feature Request] Do not hardcode input and output directories, but make them command-line-option selectable and defaulting to be inside user's home, e.g. `~/.tingle/`.

[dreirund]

Hardcoding input and output directories are a big hindrance for proper distribution packaging of this software.

I hereby feature request that the user has to or can specify the input and output directories by command line options, e.g. -i <inputdir> and -o <outputdir>, and maybe if not specified you default not to something which is a sub-directory of main.py, but which resides in the user's home directory, e.g. ~/.tingle/input/ and ~/.tingle/output/ on unixoid systems, and something similar on Windows.

Regards!