Opentelemetry initializer

[dinosath]

I thought of adding an opentelemetry initializer in the locos extras. Where should i add documentation for this initializer? Because in order for this one to work we need to have to turn off the init_logger

[jondot]

@dinosath thanks for this! looks really great!
For now, you can include a README.md right next to your initializer folder (ie turn opentelemetry.rs into a folder with a mod.rs and README.md). We'll include links to all of the README.md's in the docs eventually.

[dinosath]

Done

[jondot]

Looks good -- can you run fmt on the code?