[clang] Fix documentation markup in the Clang release notes and langu…

…age extension docs. (#85310)

clang/docs/LanguageExtensions.rst

@@ -3444,7 +3444,7 @@ Query for this feature with ``__has_builtin(__builtin_debugtrap)``.
 Query for this feature with ``__has_builtin(__builtin_trap)``.
 
 ``__builtin_arm_trap``
-------------------
+----------------------
 
 ``__builtin_arm_trap`` is an AArch64 extension to ``__builtin_trap`` which also accepts a compile-time constant value, encoded directly into the trap instruction for later inspection.
 

clang/docs/ReleaseNotes.rst

@@ -205,15 +205,15 @@ Attribute Changes in Clang
   to certain C++ class types, such as smart pointers:
   ``void useObject(std::unique_ptr<Object> _Nonnull obj);``.
 
-  This works for standard library types including ``unique_ptr``, ``shared_ptr``
-  and ``function``. See `the attribute reference
-documentation <https://llvm.org/docs/AttributeReference.html#nullability-attributes>`_
-for the full list.
+  This works for standard library types including ``unique_ptr``, ``shared_ptr``,
+  and ``function``. See
+  `the attribute reference documentation <https://llvm.org/docs/AttributeReference.html#nullability-attributes>`_
+  for the full list.
 
 - The ``_Nullable`` attribute can be applied to C++ class declarations:
   ``template <class T> class _Nullable MySmartPointer {};``.
 
-  This allows the ``_Nullable`` and ``_Nonnull` family of type attributes to
+  This allows the ``_Nullable`` and ``_Nonnull`` family of type attributes to
   apply to this class.
 
 Improvements to Clang's diagnostics