Switch to side-by-side view

--- a/src/sampleconf/mimeview
+++ b/src/sampleconf/mimeview
@@ -20,6 +20,7 @@
 application/x-all = xdg-open %f
 
 application/epub+zip = ebook-viewer %f
+application/x-mobipocket-ebook = ebook-viewer %f
 
 application/x-kword = kword %f
 application/x-abiword = abiword %f