docs: Improve wording of documentation section
docs: Improve wording of documentation section

This is a general readability improvement. The meaning of these
paragraphs has not changed.

ghalse/simplesamlphp,dnmvisser/simplesamlphp,ghalse/simplesamlphp,simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp,simplesamlphp/simplesamlphp,ghalse/simplesamlphp,simplesamlphp/simplesamlphp,ghalse/simplesamlphp,simplesamlphp/simplesamlphp,dnmvisser/simplesamlphp,dnmvisser/simplesamlphp