mention 'additional' and 'extensible' annotations

Author: ginsbach

docs/codeql/ql-language-reference/annotations.rst

@@ -16,9 +16,9 @@ For example, to declare a module ``M`` as private, you could use:
     }
 
 Note that some annotations act on an entity itself, whilst others act on a particular *name* for the entity:
-  - Act on an **entity**: ``abstract``, ``bindingset``, ``cached``, ``external``, ``language``,
+  - Act on an **entity**: ``abstract``, ``bindingset``, ``cached``, ``extensible``, ``external``, ``language``,
     ``override``, ``pragma``, and ``transient``
-  - Act on a **name**: ``deprecated``, ``final``, ``library``, ``private``, and ``query``
+  - Act on a **name**: ``additional``, ``deprecated``, ``final``, ``library``, ``private``, and ``query``
 
 For example, if you annotate an entity with ``private``, then only that particular name is
 private. You could still access that entity under a different name (using an :ref:`alias <aliases>`).

docs/codeql/ql-language-reference/ql-language-specification.rst

@@ -933,7 +933,8 @@ A predicate definition adds a mapping from the predicate name and arity to the p
 
 When a predicate is a top-level clause in a module, it is called a non-member predicate. See below for "`Member predicates <#member-predicates>`__."
 
-A valid non-member predicate can be annotated with ``cached``, ``deprecated``, ``external``, ``transient``, ``private``, and ``query``. Note, the ``transient`` annotation can only be applied if the non-member predicate is also annotated with ``external``.
+A valid non-member predicate can be annotated with ``additional``, ``cached``, ``deprecated``, ``extensible``, ``external``, ``transient``, ``private``, and ``query``.
+Note, the ``transient`` annotation can only be applied if the non-member predicate is also annotated with ``external``.
 
 The head of the predicate gives a name, an optional *result type*, and a sequence of variables declarations that are *arguments*:
 
@@ -979,7 +980,7 @@ A class type is said to *final inherit* from base types that are final or refere
 
 A class adds a mapping from the class name to the class declaration to the current module's declared type environment.
 
-A valid class can be annotated with ``abstract``, ``final``, ``library``, and ``private``. Any other annotation renders the class invalid.
+A valid class can be annotated with ``abstract``, ``additional``, ``final``, ``library``, and ``private``. Any other annotation renders the class invalid.
 
 A valid class may not inherit from itself, or from more than one primitive type. The set of types that a valid class inherits from must be disjoint from the set of types that it final inherits from.