Changing the default .txt-extension for pages

Hi,

Is it in a simple way possible to change the default ".txt"-extension for zim pages to another extension, let's say ".text" or whatever? By simple I mean, do I just have to change a handful of occasions where ".txt" appears in the source code, or is the .txt hard check more complex?
Reason: .txt-files appear very widely in many data collections and it seems much less of a hassle to tell zim to take another file extension as default than to abandon the .txt-extension for any other use.

Thanks.