SR-WLED beta version 0.13.0-b3

This is update serves to keep Sound Reactive WLED current with WLED releases.

HUGE thank you to @ewoudwijma for all of his hard work on the items below!

Changes to SR-WLED:

• NEW Dynamic Sliders and Color Control!
• Support multiple matrix panels and multiple matrix panel layouts in Led Preferences
• Support multiple 2D segments (start is top left, stop is bottom right of 2D Segment in Segment UI)
• Support 2d Segment rotation (Add Rotation and Reverse X/Y in Segment UI)
• Show slider labels and search in pc mode

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Welcome to WLED 0.13.0-b3 "Toki"!

Time is the most valuable thing in the world. So let's use it right!

This version's highlights are (in addition to the ones from 0.13.0-b2)

• Segment names:
  Never forget which segment controls what again!
• Sync groups:
  Easily set up to 8 different groups to sync effects, rather than fiddling with ports
• Increased maximum segments to 16 (ESP8266) / 32 (ESP32) (experimental, please test) and segment data limit
• Improved various effects
• Added 15 new palettes from the sound reactive fork
• Added custom CSS skinning and custom holiday background feature
• Fixed several issues related to transitions
• A heap of other fixes and improvements
• Thank you to @blazoncek for adding a lot of these features!

See the changelog for a complete list of changes!