This commit adds placeholder Go programs to the `examples` directory for
all of Borg's features. This provides a clear roadmap for future
implementation and ensures that we have a testing strategy for each
function.
The new placeholder examples are:
- `examples/all`
- `examples/collect_github_release`
- `examples/collect_github_repo`
- `examples/collect_github_repos`
- `examples/collect_pwa`
- `examples/collect_website`
- `examples/serve`
