Help: Add notes for topic 'add-link-search-static-properties-defaults'

Help/release/dev/add-link-search-static-properties-defaults.rst

+add-link-search-static-properties-defaults
+------------------------------------------
+
+* New :variable:`CMAKE_LINK_SEARCH_START_STATIC` and
+  :variable:`CMAKE_LINK_SEARCH_END_STATIC` variables were
+  introduced to initialize the
+  :prop_tgt:`LINK_SEARCH_START_STATIC` and
+  :prop_tgt:`LINK_SEARCH_END_STATIC` target properties,
+  respectively.