Fix typo in docs. NFC (#24003)

Author: midzer

site/source/docs/tools_reference/settings_reference.rst

@@ -3188,7 +3188,7 @@ overhead for the extra instrumented function indirection.  Enable this if you
 want Emscripten to handle unhandled exceptions nicely at the cost of a few
 bytes extra.
 Exceptions that occur within the ``main`` function are already handled via an
-alternative mechanimsm.
+alternative mechanism.
 
 Default value: false