Add std::underlying_type "See also" link in C2154 error reference

Rageking8 · web-flow · commit fade1318e60a · 2025-09-21T21:38:27.000+08:00
diff --git a/docs/error-messages/compiler-errors-1/compiler-error-c2154.md b/docs/error-messages/compiler-errors-1/compiler-error-c2154.md
@@ -30,3 +30,7 @@ __underlying_type(int) i;   // C2154
 __underlying_type(E) e;     // OK
 __underlying_type(EC) ec;   // OK
 ```
+
+## See also
+
+[`underlying_type` class](../../standard-library/underlying-type-class.md)
