Overwork warning flags (#2936)

* ⚗️ update warning flags

include/nlohmann/detail/macro_scope.hpp

@@ -38,8 +38,9 @@
 
 // disable documentation warnings on clang
 #if defined(__clang__)
-    #pragma GCC diagnostic push
-    #pragma GCC diagnostic ignored "-Wdocumentation"
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wdocumentation"
+    #pragma clang diagnostic ignored "-Wdocumentation-unknown-command"
 #endif
 
 // allow to disable exceptions

include/nlohmann/detail/macro_unscope.hpp

@@ -1,8 +1,8 @@
 #pragma once
 
-// restore GCC/clang diagnostic settings
+// restore clang diagnostic settings
 #if defined(__clang__)
-    #pragma GCC diagnostic pop
+    #pragma clang diagnostic pop
 #endif
 
 // clean up