add PyCharm generated folder to the gitignore.
add PyCharm generated folder to the gitignore.

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