Update README.rst

Author: zkytony

README.rst

@@ -3,11 +3,10 @@ pomdp_py
 
 `pomdp_py <https://h2r.github.io/pomdp-py>`_ is a framework to build and solve POMDP problems, written in Python and Cython.
 
-**Why pomdp_py?** It provides a POMDP framework in Python with clean and intuitive interfaces. This makes POMDP-related research or projects accessible to more people. It also helps sharing code and developing a community
+**Why pomdp_py?** It provides a POMDP framework in Python with clean and intuitive interfaces. This makes POMDP-related research or projects accessible to more people. It also helps sharing code and developing a community.
 
 Please refer to the `full documentation <https://h2r.github.io/pomdp-py>`_ and `installation instructions <https://h2r.github.io/pomdp-py/html/installation.html>`_.
 
-
 If you find this library helpful to your work, please cite the `following paper <https://arxiv.org/pdf/2004.10099.pdf>`_::
 
     @inproceedings{zheng2020pomdp_py,
@@ -18,3 +17,6 @@ If you find this library helpful to your work, please cite the `following paper
       url = {https://icaps20subpages.icaps-conference.org/wp-content/uploads/2020/10/14-PlanRob_2020_paper_3.pdf},
       note = {Arxiv link: "\url{https://arxiv.org/pdf/2004.10099.pdf}"}
    }
+
+
+**Call for Contributions**: please check out - `h2r/pomdp-py/issues/25 <https://github.com/h2r/pomdp-py/issues/25>`_.