Part of https://github.com/envoyproxy/envoy/issues/10355, this patch introduces additional
annotations to the API to support automatic inference (and developer documentation) of where the
active developer editable version of a file is, and which files are frozen or machine generated.
Risk level: Low (API annotations only)
Testing: CI
Signed-off-by: Harvey Tuch <htuch@google.com>
Mirrored from https://github.com/envoyproxy/envoy @ 4c5f4310bb8a19a38e5377d7a2d2dc6aa4560f47