export menu alignment broken

[andreyorst]

Also happens in emacs -q:

[kaushalmodi]

Hmm, looks like I cannot have those key binding descriptions too long. I'll fix this. Thanks.

[kaushalmodi]

Now we will see something like this:

Note that I chose not to align the second column with the rest of the export options because trying to do so was forcing me to make the descriptions too cryptic.