[Task]: Validate playground snippets in website documentation

[Amar3tto]

What needs to happen?

Playground snippet example:

{{< playground height="700px" >}} {{< playground_snippet language="py" path="SDK_PYTHON_FlatMapLambda" show="flatmap_lambda" >}} {{< /playground >}}

We need to check that there is a correct .py file with name: FlatMapLambda and it has [START flatmap_lambda] and [END flatmap_lambda]. This validation is needed for all Python/Java playground snippets.

Issue Priority

Priority: 2 (default / most normal work should be filed as P2)

Issue Components

• [ ] Component: Python SDK
• [ ] Component: Java SDK
• [ ] Component: Go SDK
• [ ] Component: Typescript SDK
• [ ] Component: IO connector
• [ ] Component: Beam YAML
• [X] Component: Beam examples
• [X] Component: Beam playground
• [ ] Component: Beam katas
• [ ] Component: Website
• [ ] Component: Spark Runner
• [ ] Component: Flink Runner
• [ ] Component: Samza Runner
• [ ] Component: Twister2 Runner
• [ ] Component: Hazelcast Jet Runner
• [ ] Component: Google Cloud Dataflow Runner

[Amar3tto]

.take-issue