Documentation for v0.1 version (#199)

* Adding Equations, solving typos
* improve _code.rst
* the team rst and restuctore index.rst
* fixing errors

---------

Co-authored-by: Dario Coscia <dariocoscia@dhcp-015.eduroam.sissa.it>

docs/source/_team.rst

@@ -0,0 +1,24 @@
+PINA Team
+==============
+
+PINA is currently developed by `Dario Coscia <https://github.com/dario-coscia>`_, `Nicola Demo <https://github.com/ndem0>`_, and `Anna Ivagnes <https://github.com/annaivagnes>`_
+under the supervision of `Prof. Gianluigi Rozza <https://mathlab.sissa.it/people/gianluigi-rozza>`_ in the `SISSA MathLab <https://mathlab.sissa.it/>`_ group.
+
+A significant part of PINA has been written either as a by-product for other projects people were funded for, or by people on university-funded positions.
+There are probably many of such projects that have led to some development of PINA. We are very grateful for this support!
+In particular, we acknowledge the following sources of support with great gratitude:
+
+* `H2020 ERC CoG 2015 AROMA-CFD project 681447 <https://people.sissa.it/~grozza/aroma-cfd/>`_, P.I. Professor `Prof. Gianluigi Rozza <https://mathlab.sissa.it/people/gianluigi-rozza>`_ at `SISSA MathLab <https://mathlab.sissa.it/>`_.
+* `Next Generation EU <https://www.agenziacoesione.gov.it/dossier_tematici/nextgenerationeu-e-pnrr/>`_ for ambiental and digital transitionfor, Italy.
+
+.. figure:: index_files/foudings.png
+    :align: center
+    :width: 400
+
+We also acknowledge the contribuition of `Maria Strazzullo <https://mstrazzu.github.io/>`_ in the early developments of the package. A special
+thank goeas to all the students and researchers from different universities which contributed to the package. Finally we warmly thank all the
+`contributors <https://contrib.rocks/preview?repo=mathlab%2Fpina>`_!
+
+.. figure:: index_files/university_dev_pina.png
+    :align: center
+    :width: 500