There are two circuits to build: the necklace itself and the ItsyBitsy + power housed inside the case. These are connected via the USB MicroB counterparts. These diagrams will detail which circuit connections need to be made, but we'll go over assembly in more detail later.

ItsyBitsy and Power Circuit

Note that the diagram above doesn't show the exact placement of the components -- it was laid out so that you can easily see the wire connections. Also note that this wiring means that the slide switch will turn off battery power, but it has no effect if the ItsyBitsy is connected to USB.

Here is a table for the connections illustrated above to help make it more clear:

To make the slide switch a power switch, cut the copper trace between the two through-hole connectors on the LiPo backpack next to the 5V hole, and solder two wires through those to the slide switch.

To support capacitive touch on D11, connect a 1MΩ resistor from D11 to Ground. 

Necklace LED Matrix Circuit

The above diagram is a representation of the circuit connections that need to be made between the DotStar 8x8 Matrix and the USB MicroB plug. Note that there is a single MicroB plug pictured, with both of its sides showing.