Fix uncaught exceptions section

Author: hoodmane

peps/pep-0776.rst

@@ -387,8 +387,9 @@ compatible version of Emscripten, it will automatically pick up support for
 wheels with vendored dynamic libraries.
 
 
+-----------------------------
 Traps and Uncaught Exceptions
-=============================
+-----------------------------
 
 We consider the C runtime state to be corrupted if there is a WebAssembly trap,
 an unhandled JavaScript exception, or an uncaught WebAssembly throw instruction.