Add an example notebook with analyses for the Top 12 German companies (#1024)

* Add an example notebook with analyses for the Top 12 German companies

* add description for cells in notebook

* Add example for top German companies to README

Author: devcrocod

examples/README.md

@@ -32,6 +32,9 @@ ___
 * titanic ([notebook](notebooks/titanic/Titanic.ipynb)/[Datalore](https://datalore.jetbrains.com/view/notebook/B5YeMMONSAR78FgKQ9yJyW)) –
 Let's see how the new library will show itself on the famous Titanic dataset.
 ___
+* top 12 German companies ([notebook](notebooks/top%2012%20german%20companies)/[Datalore](https://datalore.jetbrains.com/report/static/KQKedA4jDrKu63O53gEN0z/MDg5pHcGvRdDVQnPLmwjuc)) –
+  Analyze key financial metrics for several major German companies.
+___
 * wine ([notebook](notebooks/wine/WineNetWIthKotlinDL.ipynb)/[Datalore](https://datalore.jetbrains.com/view/notebook/aK9vYHH8pCA8H1KbKB5WsI)) –
   Wine. Kotlin Dataframe. KotlinDL. What came out of this can be seen in this notebook.
 ___