Add documentation for restarting from a seed mechanism

documentation/source/users/rmg/input.rst

@@ -934,3 +934,32 @@ For example ::
 		maxNumSpecies=100
 	)
 
+Restarting from a Seed Mechanism
+=================================
+The preferred method for restarting an RMG-Py job is to restart the job from a seed mechanism. There are many scenarios
+when the user might want to do this, including continuing on a job that ran out of time or crashed as the result of a
+now fixed bug. To restart from a seed mechanism, the block below must be added on to the input file.  ::
+
+    restartFromSeed(path='seed',
+                    relative_path=True,  # This by default is True, so you only have to include this if False
+                    )
+
+The ``path`` flag is the path to the seed mechanism folder, which contains three subfolders that must be titled as
+follows: Filters, Seed, Seed_Edge. By default this path is relative to the location of the input.py file, but setting
+the ``relative_path`` flag to False will instead treat the path as an absolute path on disk.
+
+Then, to restart from the seed mechanism the input file is submitted as normal. ::
+
+    python rmg.py input.py
+
+Once the restart job has begun, RMG will move the seed mechanism files to a new subfolder in the output directory
+entitled ``restart``. This is to back-up the seed mechanism used for restarting, as everything in the ``seed`` subfolder
+of the output directory is overwritten by RMG during the course of mechanism generation.
+
+RMG also outputs a file entitled ``restart_from_seed.py`` the first time a seed mechanism is generated during the course
+of an RMG job (so long as the RMG job was not itself a restarted job). This file is an exact duplicate of the original
+input file with the exception that the restart block has been added on automatically for convenience. In this way this
+file is treated in the exact way as a normal input file.
+
+Finally, **note that it is advised to turn on generating the seed each iteration so that you can restart an RMG job right where it left off**.
+This can be done by setting ``generateSeedEachIteration=True`` in the options block of the input file.