Fix typo docs

docs/source/_rst/_installation.rst

@@ -0,0 +1,34 @@
+Installation
+============
+
+**PINA** requires requires `numpy`, `scipy`, `matplotlib`, `future`, `torch`, `sphinx` (for the documentation) and `pytest` (for local test). The code is tested for Python 3, while compatibility of Python 2 is not guaranteed anymore. It can be installed using `pip` or directly from the source code.
+
+Installing via PIP
+__________________
+
+Mac and Linux users can install pre-built binary packages using pip.
+To install the package just type:
+
+.. code-block:: bash
+
+    $ pip install git+https://github.com/mathLab/PINA.git
+
+To uninstall the package:
+
+.. code-block:: bash
+
+    $ pip uninstall pina
+
+Installing from source
+______________________
+The official distribution is on GitHub, and you can clone the repository using
+
+.. code-block:: bash
+    
+    $ git clone https://github.com/mathLab/PINA
+
+To install the package just type:
+ 
+.. code-block:: bash
+
+    $ pip install -e .