accept docm file

[miko53]

I see that docm files are rejected as not supported.
Is it possible to accept them ?

In fact the format is the same (except macro support), and when I renaming file the file is correctly read.

As with this lib I want just retrieve text and paragraph, rename file seems useless

May be add a disclaimer to indicate that macro are not supported ?

The modification seems easy (accept docm in document.rb line 28)

What do you think about this ?

Thanks a lot!