Add license file for use

[cliffchapmanrbx]

Hi team, our legal department is asking us to clarify what license this code is released under. It seems like it's Apache 2.0 like the main envoy repo, but we would appreciate clarification by adding an explicit license file to this repo.

I tried looking for other license questions in the repo but didn't find any.

Thank you!

[phlax]

It seems like it's Apache 2.0 like the main envoy repo

yep, CNCF projects are Apache 2 licensed

this repo still needs to display the license tho - i think its just a matter of creating a PR to add LICENSE.txt