updated V1.8 SKR V1.3; added missing wiring diagram; this PR need PR#228

[GadgetAngel]

this PR needs PR #228 so it can work properly. It contains a link to the information in PR #228

• updated the BTT SKR V1.3 file (v1_skr13_uart_wiring.md) reused the following from another setup: a. skrv13_RaspberryPi.md b. skr_v13_Resources.md
• added initial Removal of Jumpers pictures for SKR v1.3 in UART mode only
• added Initial Preparation - Set Jumpers pictures for SKR v1.3 in UART mode only
• Added Voltage Selections for SKR v1.3 in UART mode
• added initial preparation - Set Jumpers diagram for BTT SKR V1.3 in UART mode
• added a check box next to each item on the MCU description so the user can check of the items as he goes, if he wants. I had to enable the check boxes to be interactive by adding a JS function to the v1_skr13_uart_wiring.md file. New function called "enable_checkboxes();"
• added a term definition for BAT85 below the MCU description
• added section about Stepper Motor Drivers
• Added wiring diagram for Voron V1.8 BTT SKR V1.3 in UART mode
• Added the ability to download the wiring diagrams
• added the heatsink diagram to remind user to ensure that the heatsinks are installed on the stepper motor drivers in UART Mode
• added a note to help the user orient the heat sinks properly on the step stick boards.
• added the description about BTT SKR V1.3 UART serial communications with Raspberry pi with diagram
• added a diagram showing how to hook up independent power supply for Raspberry pi
• added SSR wiring diagram using BTT SKR V1.3 in UART mode
• added the ability to download the SSR wiring diagrams
• added the Color Pin diagram for BTT SKR V1.3
• Added link so Voron users can download the Color PIN diagram from this page in both .pdf and .jpg format
• Added the ability to examine the Color PIN diagram with ZOOM function
• added original BTT SKR V1.3 pinout
• added "if pin diagrams do not match check the schematic diagram" section, provide link to BTT SKR V1.3 schematic diagram
• Added the ability to examine the original pinout diagram with ZOOM capability
• compressed all pictures and diagrams so the page load time is fast.
• Checked these pages by running the server locally on my Windows machine, then if everything works, uploaded them to my LIVE TEST Voron Docs site at https://gadgetangel.org so I can see if there are any interactions between all the pull requests I have submitted thus far.