Add Python documentation for takeVariable method on component.
Add Python documentation for takeVariable method on component.

cellml/libcellml,cellml/libcellml,hsorby/libcellml,MichaelClerx/libcellml,nickerso/libcellml,hsorby/libcellml,nickerso/libcellml,hsorby/libcellml,nickerso/libcellml,MichaelClerx/libcellml,cellml/libcellml,MichaelClerx/libcellml,cellml/libcellml,hsorby/libcellml,nickerso/libcellml