Fix comments

src/Charge.c

src/Charge.h

src/Point.c

src/Point.h

src/Rectangle.c

src/Rectangle.h

src/Simulation.c

src/Simulation.h

src/Vector2.c

src/Vector2.h

src/constants.c

src/constants.h

src/main.c

src/random_number.c

src/random_number.h