[Project] Readme minor fixes

Author: EgorOrachyov

README.md

@@ -60,12 +60,21 @@ prototyping algorithms on a local computer for later running on a powerful serve
 ## Installation
 
 If you running OS **Ubuntu 20.04** or higher you can download the official
-PyPI **pycubool** python package, which includes compiled CPP library source
-with Cuda and Sequential computations supports. Installation process 
-requires only `python3` to be installed on your machine. 
+PyPI **pycubool** python package, which includes compiled library source
+with Cuda and Sequential computations support. Installation process 
+requires only `python3` to be installed on your machine. Python can be installed 
+as follows [link](https://phoenixnap.com/kb/how-to-install-python-3-ubuntu).
+
+If all requirements satisfied, run the following command to install PyPI package:
+```shell script
+$ python3 -m pip install -i https://test.pypi.org/simple/ pycubool
+``` 
 
 ## Getting Started
 
+This section gives instructions to build the library from sources.
+These steps are required if you want to build library for your specific platform with custom build settings.
+
 ### Requirements
 
 - Linux Ubuntu (tested on 20.04)