docs: revisit examples readme (#725)

Signed-off-by: Jan Kowalleck <[email protected]>

Author: jkowalleck

examples/README.md

@@ -1,8 +1,11 @@
 # Examples
 
+## Usage
+
 * [Build & Serialize](complex_serialize.py)
 * [Deserialize](complex_deserialize.py)
 
-----
+## Data models
 
-see examples how to use data models in the [test data](../tests/data.py)
+The [`models` test data](../tests/_data/models.py) holds also examples for complete structures
+with all possible use cases, all nesting, and advanced complexity.