Updated installation page in docs to follow the package structure whe…

…re error_propagation is installed seperately

docs/source/install.rst

@@ -1,15 +1,16 @@
 Installation
 ============
-
-(Install through pip is not supported, yet) The easiest way to install the package is through pip, simply run:
+The Pseudobatch Python package can be install through PYPI using pip. Most of the functionality can be installed simply by calling
 
 .. code-block:: bash
 
     pip install pseudobatch
 
-Then you ready to go! Alternatively, you can download the source code from
-GitHub and install it manually:
+The error propagation functionality requires installation of cmdstanpy and CmdStan. Please see the cmdstanpy documentation for how to install both cmdstanpy and CmdStan in your specific setup (https://mc-stan.org/cmdstanpy/installation.html). After successfully installing both proceed to install the remaining dependencies of the error propagation module through pip.
 
 .. code-block:: bash
 
-    python setup.py install
+    pip install pseudobatch[error_propagation]
+
+Now the error propagation module is installed and ready to use. Note that the first time you import the error propagation module CmdStan will compile the Stan model this will take several minutes.
+