update mobi convert section

README.md

@@ -98,12 +98,20 @@ Options:
 
 ## Reading mobi files
 
-`epuppy`   doesn't   support  mobi   files,   but   you  can   install
-[mobitool](https://github.com/bfabiszewski/libmobi/)  and  use  it  to
-convert mobi files to epub. The ubuntu package is `libmobi-tools`. To convert, execute: 
+`epuppy`   doesn't   support  mobi   files,   but   you  can easily
+convert them to epub format using calibre, which contains a tool named
+`ebook-convert`. You can install it on Ubuntu with:
+
+`apt install calibre`
+
+On Fedora use:
+
+`dnf install ebook-tools`
+
+To convert, execute: 
 
 ```default
-mobitool -e somebook.epub
+ebook-convert somebook.mobi somebook.epub
 ```
 
 ## Installation