add docs for --gskip and --burnin

Author: orbeckst

docs/source/tutorial.rst

@@ -50,6 +50,15 @@ plot that correspond to the TM segments of the protein (figures 7-10). Your
 protein can be added to ``basicrta/basicrta/data/tm_dict.txt`` in the same
 format as the existing proteins. 
 
+Optional parameters ``--gskip`` and ``--burnin`` can be used to control the 
+Gibbs sampler processing. The ``--gskip`` parameter specifies the skip interval
+for decorrelated samples (default: 1000), while ``--burnin`` sets the number 
+of initial samples to discard during equilibration (default: 10000). The 
+default values are taken from the `research paper <https://doi.org/10.1021/acs.jctc.4c01522>`_. ::
+
+  python -m basicrta.cluster --niter 110000 --nproc 3 --cutoff 7.0 --prot b2ar \
+  --gskip 1000 --burnin 10000
+
 ``basicrta.cluster`` will process the Gibbs samplers, compute :math:`\tau` for
 each residue, plot :math:`\tau` vs resid, and write the data to ``tausout.npy``
 (see next section). If a structure is passed to the script, the b-factors of the