Update docus.

docs/design/SemanticTokens-example.cpp

@@ -0,0 +1,28 @@
+// This is an example file that shows the usage of semantic tokens.
+// clang-format off
+
+
+    char character = 'a';
+//    ^               ^
+//  keyword       character
+
+     int number = 1;
+//    ^           ^
+//  keyword     number
+
+    const char* string = "Hello, World!";
+//    ^                     ^    
+//  keyword               string
+
+    #pragma      once
+//     ^           ^
+// directive     pragma
+
+    #include     <cstdio>
+//     ^           ^
+// directive     header
+
+    #define      MAX 100
+//     ^          ^
+// directive    macro
+