Provide a build-able example (perhaps in a separate repo) that can be used as an unit test in CI

[thedeadliestcatch]

Based off the issues everyone seems to be experiencing using this as a component, I think the ideal scenario would be to provide an example repo that settles on one approach to successfully build any of the examples.

This will also allow a proper CI stage chain to verify against esp-idf as versions get released.

[thedeadliestcatch]

I have tested #10, #9 and #5. None of the suggested solutions or references will work.

For example, the "hack" involving the full copy of the library into a component with a new CMake configuration will not result in the correct linker references.

The hello world example is also broken. The examples at least in this tree are correct (ex. bus.i2c union, other code refers to .sda directly).