repo: move main.go to examples, and add more examples

`jsonrpsee` repo has a good example layout, lets use it the same way

Start by inspecting main.go and the existing examples layout, then compare it with the jsonrpsee repository's example organization. Determine which functionality should move into examples and what additional examples are required; done means the repository follows the intended layout and the examples build successfully.

Written by the indexing model from the issue text.