Add Trident SKR v1.3 wiring diagram, This PR will not work properly without PR #233

[GadgetAngel]

Add Trident SKR v1.3 wiring diagram, This PR will not work properly without PR #233 It contains a link to the information in PR #233

updated Electrical Index.md file to add the Trident SKR V1.3 (tri_skrv13_uart_wiring.md)

used two additional files: a. skrv13_Resources.md b. skrv13_RaspberryPi.md

*added initial Removal of Jumpers diagram *added initial preparation - Set Jumpers diagram for SKR V1.3 *updated description for wiring diagram in SKR V1.3 *added wiring diagram for Trident - SKR V1.3 in UART mode *added the heatsink diagram to remind user to ensure that the heatsinks are installed on the stepper motor drivers for:

1. MCU XYE with heat sinks
2. MCU Z with heat sinks

*added SSR wiring diagram using SKR V1.3 *Updated Color Pin diagram for Bigtreetech SKR V1.3 *added original SKR V1.3 pinout *added URL to the original Bigtreetech Github Repo on the SKR V1.3 board