Fixed Rotate Image Example Syntax

There was an error in how we cited the syntax for a rotate image request. Changed this incorrect example -- `http://static.thewalters.org/images/PS1_61.347_Fnt_DD_T08.jpg?rotate=angle-54|bgcolor-fff' to a correct example -- `http://static.thewalters.org/images/PS1_61.347_Fnt_DD_T08.jpg?rotate=54|bgcolor-fff`.