Add support for files without header

[smoia]

Detailed Description

#41 was closed trough a couple of PRs, but we don't support txt files without header yet.
We decided that it's not important before our main release, so this issue is to remind us that we'll have to do it, but it's definitely not fundamental.

Possible Implementation

Either we add a lot of optional arguments for the command line, or we read a file that contains such information - maybe another script could help the user create this file (a json?)

[vinferrer]

I would close the issue, either adding optional arguments or the second option of reading a different file is too costly for the reward

[smoia]

Let's not close the issue, and kep it to remind us that there is this enhancement we can work on at a later date - that's the meaning of the label "Paused".
If we can add a way to automatically recognise the channels, it will become a bit easier to deal with this problem as well.