Add core species list usage to documentation

Adds an example of how to use the coreSpeciesList option in an input file to read in core species from an external species dictionary

Author: sevyharris

documentation/source/users/rmg/input.rst

@@ -247,6 +247,14 @@ The following is an example of a typical species item, based on methane using SM
 			"""
 	)
 
+For long lists of initial core species, you can specify a coreSpeciesList, shown below::
+
+    coreSpeciesList(
+        species_dictionary_file="path/to/your/species_dictionary.txt"
+    )
+
+This specifies the path for an RMG-formatted :ref:`species dictionary <the_chemkin_folder>` from which additional species will be loaded. Note that RMG will complain if any species in the input file is duplicated in the species dictionary.
+
 .. _forbidden_structures:
 
 Forbidden Structures

documentation/source/users/rmg/output.rst

@@ -13,6 +13,9 @@ You will see that a sucessfully executed RMG job will create multiple output fil
 ``/species``  
 ``RMG.log``
 
+
+.. _the_chemkin_folder:
+
 ------------------
 The Chemkin Folder
 ------------------