Fix some issues.

Author: Yuncong Zhang

Documentation~/com.unity.uiwidgets.md

@@ -1,5 +1,4 @@
 # UIWidgets
-[中文](README-ZH.md)
 
 
 ## Introduction
@@ -354,4 +353,4 @@ Meanwhile, you can join the discussion channel at (https://connect.unity.com/g/u
 
 ## How to Contribute
 
-Check [CONTRIBUTING.md](CONTRIBUTING.md)
+Check [CONTRIBUTING](CONTRIBUTING)

Documentation~/index.md

@@ -1,5 +1,4 @@
 # UIWidgets
-[中文](README-ZH.md)
 
 
 ## Introduction
@@ -354,4 +353,4 @@ Meanwhile, you can join the discussion channel at (https://connect.unity.com/g/u
 
 ## How to Contribute
 
-Check [CONTRIBUTING.md](CONTRIBUTING.md)
+Check [CONTRIBUTING](CONTRIBUTING)

Runtime/ui/txt/emoji.cs

@@ -509,7 +509,7 @@ public static bool isSingleCharNonEmptyEmoji(int c) {
         }
 
         public static bool isEmptyEmoji(int c) {
-            return !emojiLookupTable.ContainsKey(c) && c == 0xFE0F;
+            return c == 0xFE0F && !emojiLookupTable.ContainsKey(c);
         }
 
         public static List<string> splitByEmoji(string text) {