FEM: guiobjects directory, add a readme

src/Mod/Fem/CMakeLists.txt

@@ -347,6 +347,7 @@ SET(FemGuiViewObjects_SRCS
 
 SET(FemGuiScripts_SRCS
     femguiobjects/__init__.py
+    femguiobjects/readme.md
 )
 
 SET(FemGuiUtils_SRCS

src/Mod/Fem/femguiobjects/readme.md

@@ -0,0 +1,4 @@
+# Information
++ The view providers where moved to the directory femviewproviders.
++ This directory is kept some time because there are some dev branches around.
++ Some of these would no longer rebase if the directory will be deleted.