Enhancement: Add option for RGBA only output

Author: ERSUCC

typescripts/Main.ts

@@ -22,6 +22,7 @@ declare global {
     advanced: Picker
 
     injectCSS:           (css: Str)                 => void
+    useRGBAOnlyPicker:   ()                         => void
     useNumAndRGBAPicker: ()                         => void
     useNumberOnlyPicker: ()                         => void
     useNonPickPicker:    ()                         => void
@@ -186,6 +187,10 @@ window.useNumAndRGBAPicker = (): void => {
   window.advanced = new Picker(document, new Set([NLNumber, RGBA]))
 }
 
+window.useRGBAOnlyPicker = (): void => {
+  window.advanced = new Picker(document, new Set([RGBA]))
+}
+
 window.setValue = (typ: Str, value: any): void => {
 
   let repr = undefined