Create "README.md" file.

[szymon-filipiak]

Good open-source projects have readable and extensive README.md file.

We should create one for our repository, where we will define:

• the goals of our project,
• requirements for application,
• how to install and run the application.

For reference on how to write good README files see this or this.

Please also utilize markdown language capabilities to make it readable and attractive visually.