- updated instructions of setuptools to include external references

Author: doublebyte1

docs/source/installation.rst

@@ -47,14 +47,8 @@ For developers and the truly impatient
 .. note::
 
    If you get this error: `ModuleNotFoundError: No module named 'setuptools'`, it is because `setuptools` 
-   is not installed in your system. Although some python installers will install it, `setuptools` is not part of the Python standard library. 
-   
-   Install it with:
-   
-   .. code-block:: bash
-
-      pip3 install setuptools   
-
+   is not installed in your system. Although some python installers will install it, `setuptools` is `not part of the Python standard library <https://docs.python.org/3/py-modindex.html#cap-s>`_. 
+   See this `guide <https://packaging.python.org/en/latest/guides/installing-using-linux-tools/>`_ to install it in your system.
 
 pip
 ---