Added some documentation about install of share/keywords

opm/parser/share/CMakeLists.txt

@@ -1,3 +1,15 @@
+# The execute_process() code below asks git for a list of all the repo
+# files which should be installed; an alternative and simpler approach
+# would just be:
+#  
+#     install( DIRECTORY keywords DESTINATION ${CMAKE_INSTALL_PREFIX}/share/opm/parser/eclipse)
+# 
+# The disadvantage with that is that very easily end up installing
+# editor backup files and other pieces of garbage. The disadvantage with
+# the current setup is the list of files uis configured during the
+# install cmake configure process, and will typically be out of sync if
+# you have added more keywords.
+
 execute_process( COMMAND git ls-tree --name-only -r HEAD WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} OUTPUT_VARIABLE KEYWORD_LIST_STRING)
 string(REPLACE "\n" ";" KEYWORD_LIST ${KEYWORD_LIST_STRING})