Added some info on make install.
Added some info on make install.

JoaoRodrigues/freesasa,mittinatten/freesasa,mittinatten/freesasa,JoaoRodrigues/freesasa,mittinatten/freesasa,mittinatten/freesasa,JoaoRodrigues/freesasa,JoaoRodrigues/freesasa