- Fixed warnings for different section levels
- put all detectors in subdirectory.

	new file:   .gitignore
	new file:   InputEvents.rst
	modified:   contents.rst
	renamed:    Calorimeters.rst -> detectors/Calorimeters.rst
	renamed:    EMCalorimeterSoLID.rst -> detectors/EMCalorimeterSoLID.rst
	renamed:    RomanPot.rst -> detectors/RomanPot.rst
	new file:   detectors/Trackers.rst
	renamed:    detectors.rst -> detectors/detectors.rst