Wishlist: more visible examples, especially without option tokio

[ydirson]

tokio is mentioned as being optional, and it would be useful for newcomers to get an idea how rust-netlink can be used without it.

I'm reporting this in netlink-proto since it is the one showing example code on docs.rs. It would be really useful to have links to example code more visible, directly on https://github.com/rust-netlink/ which gives a good idea of what's in this project, but not really of where to start (which package doc to look at first, where to find examples to get you started).

Note I did find the async_std example. It does however suffer from the same problem described in #7. Providing ready-to-go Cargo.toml files for all examples would make it really easier for users to try them, and would make it possible to check in CI jobs that they are still up-to-date with current code.

Also maybe a non-async example (e.g. with use polling) can be useful (or an explicit mention that only async style is supported), as not everyone has jumped aboard the async train yet.