Add Filename Template variables for action of save page / save selection

[coldwinds]

Is your feature request related to a problem? Please describe.
To distinguish between page and selection content,
I would like to have two folder to store html files,
one for result of save page,
and one for result of save selection

Describe the solution you'd like
It would be nice to have certain {save_action} like Template variables with value of "page" and "selection".
So we can configure filename to let saved pages go to page folder, and saved selections go to selection folder

[gildas-lormeau]

Thank you for the suggestion. I added the support of the variable {save-action}. It will be available in the next version.