[Feature request] Open todo in current folder by default

[engibengi]

I think it would be cool if, when launching the Todo command, it would look for a todo list inside the current folder, without the hustle of having to specify the 'TODO_PATH=' every time.
Then, if the current folder does not have a list in itself, go and search for the home path one.
Another thing would be to add an option (like "home") to skip the lookup of the current folder.