Update document

Sources/Rings/SphericText.md

@@ -11,4 +11,19 @@ SphericText("123456")
 // Create SphericText with word list
 SphericText(words: ["123", "456", "789"])
 
+// Create SphericText and bind it with variable
+@State var degrees: CGFloat
+SphericText("123456", $degrees)
+
+// Adjust SphericText appearance
+SphericText("123456")
+    .wordSpacing(wordSpacing)           // modify space between words
+    .font(.system(size: 32.0))          // adjust font family and size
+    .wordColor(textColor)               // change text color
+    .wordBackground(backgroundColor)    // change text background color
+    .blurMinors(blurMinors)             // bluring words which are not front most
+    .rangeOfOpposite(in: 145...210)     // specify the opposite range of the most front word
+    .hideOpposite(true)                 // hide words located in opposite range
+    .perspective(perspective)           // adjust viewing point
+    .radius(radius)                     // adjust the radius of spheric
 ```