[Feature Request][Go]: Demonstrate building a pipeline from scratch using Beam Go

[lostluck]

What would you like to happen?

We have plenty of examples for the Go SDK, and a starter project, but no "building a pipeline from scratch" guide. Running prebuilt examples aren't as illustrative as a step by step introduction.

The example should remain wordcount, but clearly introducing each part one by one would help users understand their pipelines.

Issue Priority

Priority: 2 (default / most feature requests should be filed as P2)

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