Help: Place relocatable package notes in their own subsections

These notes apply only for the use case of creating a package for
redistribution on machines other than that where it is built.  Clarify
this to readers by placing the discussion in dedicated sections titled
accordingly.

Help/command/target_include_directories.rst

@@ -55,5 +55,8 @@ installation prefix.  For example:
     $<INSTALL_INTERFACE:include/mylib>  # <prefix>/include/mylib
   )
 
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. |INTERFACE_PROPERTY_LINK| replace:: :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES`
 .. include:: /include/INTERFACE_INCLUDE_DIRECTORIES_WARNING.txt

Help/command/target_link_libraries.rst

@@ -49,9 +49,6 @@ CMake will also propagate :ref:`usage requirements <Target Usage Requirements>`
 from linked library targets.  Usage requirements of dependencies affect
 compilation of sources in the ``<target>``.
 
-.. |INTERFACE_PROPERTY_LINK| replace:: :prop_tgt:`INTERFACE_LINK_LIBRARIES`
-.. include:: /include/INTERFACE_LINK_LIBRARIES_WARNING.txt
-
 If an ``<item>`` is a library in a Mac OX framework, the ``Headers``
 directory of the framework will also be processed as a
 :ref:`usage requirement <Target Usage Requirements>`.  This has the same
@@ -153,3 +150,9 @@ will not be used in OLD handling of :policy:`CMP0003` or :policy:`CMP0004`.
 See the :manual:`cmake-generator-expressions(7)` manual for available
 expressions.  See the :manual:`cmake-buildsystem(7)` manual for more on
 defining buildsystem properties.
+
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. |INTERFACE_PROPERTY_LINK| replace:: :prop_tgt:`INTERFACE_LINK_LIBRARIES`
+.. include:: /include/INTERFACE_LINK_LIBRARIES_WARNING.txt

Help/prop_tgt/INTERFACE_INCLUDE_DIRECTORIES.rst

@@ -22,5 +22,8 @@ installation prefix.  For example:
     $<INSTALL_INTERFACE:include/mylib>  # <prefix>/include/mylib
   )
 
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. |INTERFACE_PROPERTY_LINK| replace:: ``INTERFACE_INCLUDE_DIRECTORIES``
 .. include:: /include/INTERFACE_INCLUDE_DIRECTORIES_WARNING.txt

Help/prop_tgt/INTERFACE_LINK_LIBRARIES.rst

@@ -17,5 +17,8 @@ with the syntax ``$<...>``.  See the :manual:`cmake-generator-expressions(7)`
 manual for available expressions.  See the :manual:`cmake-buildsystem(7)`
 manual for more on defining buildsystem properties.
 
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. |INTERFACE_PROPERTY_LINK| replace:: ``INTERFACE_LINK_LIBRARIES``
 .. include:: /include/INTERFACE_LINK_LIBRARIES_WARNING.txt

Help/prop_tgt/LINK_INTERFACE_LIBRARIES.rst

@@ -24,5 +24,8 @@ property if policy :policy:`CMP0022` is ``NEW``.
 This property is deprecated.  Use :prop_tgt:`INTERFACE_LINK_LIBRARIES`
 instead.
 
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. |INTERFACE_PROPERTY_LINK| replace:: ``LINK_INTERFACE_LIBRARIES``
 .. include:: /include/INTERFACE_LINK_LIBRARIES_WARNING.txt

Help/prop_tgt/LINK_INTERFACE_LIBRARIES_CONFIG.rst

@@ -13,5 +13,8 @@ property if policy :policy:`CMP0022` is ``NEW``.
 This property is deprecated.  Use :prop_tgt:`INTERFACE_LINK_LIBRARIES`
 instead.
 
+Creating Relocatable Packages
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 .. |INTERFACE_PROPERTY_LINK| replace:: ``LINK_INTERFACE_LIBRARIES_<CONFIG>``
 .. include:: /include/INTERFACE_LINK_LIBRARIES_WARNING.txt