Additions and updates for techmums.

	* images/minimal-shrimp-pov-circuit.svg: Updated for cleaner
	version and 75 ohm R2.
	* ehw3-bill-of-parts.ods: Renamed from bill-of-parts.ods.
	* images/breadboard.jpeg: Created.
	* images/breadboard.png: Created.
	* images/galaxy.jpg: Created.
	* images/galaxy.png: Created.
	* images/minimal-shrimp-pov-circuit.svg: Updated for 75 ohm R2.
	* images/minimal-shrimp-pov-techmums.png: Created.
	* images/rave.jpg: Created.
	* images/rs.jpg: Created.
	* images/techmums.png: Created.
	* images/time-1.png: Created.
	* images/time-2.png: Created.
	* presentations/shrimp-pov-techmums-instructors.odp: Created.