Added new options, especially "Read less"

(1) added option for user to change animation time
(2) added option (and
corresponding code) to reverse the expansion ("Read less")
(3) edited to
allow multiple calls on same set of elements, so that dynamically added
elements can still be covered
Added a comment
Merge pull request #4 from OsakaWebbie/master

New feature: reversion of expansion ("Read less"), plus a couple minor things