Help: Fix typo in add_library(... ALIAS ...) text

Help/command/add_library.rst

@@ -123,7 +123,7 @@ Alias Libraries
 
 Creates an :ref:`Alias Target <Alias Targets>`, such that ``<name>`` can be
 used to refer to ``<target>`` in subsequent commands.  The ``<name>`` does
-not appear in the generatedbuildsystem as a make target.  The ``<target>``
+not appear in the generated buildsystem as a make target.  The ``<target>``
 may not be an :ref:`Imported Target <Imported Targets>` or an ``ALIAS``.
 ``ALIAS`` targets can be used as linkable targets and as targets to
 read properties from.  They can also be tested for existence with the