[Feature Request]: Add Colab Examples to PTransform Documentation

### What would you like to happen?

To strengthen our Beam Docs, as well as allow users to have working examples, we should integrate colab [examples](https://colab.sandbox.google.com/github/liferoad/beam/blob/learn-transforms/examples/notebooks/get-started/learn_beam_transforms_by_doing.ipynb) onto this [page](https://beam.apache.org/documentation/programming-guide/#applying-transforms).

### Issue Priority

Priority: 3 (nice-to-have improvement)

### Issue Components

- [X] Component: Python SDK
- [ ] Component: Java SDK
- [ ] Component: Go SDK
- [ ] Component: Typescript SDK
- [ ] Component: IO connector
- [X] Component: Beam examples
- [ ] 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