Proto commits in prometheus/client_rust

These 5 commits are when the Protocol Buffers files have changed:

Commit:45fed14
Author:John Howard
Committer:GitHub

protobuf: move from OpenMetrics to Prometheus proto (#298) * dependencies: update prost to 0.14 Signed-off-by: John Howard <john.howard@solo.io> * protobuf: allow compiling without `protoc` Our goal is to have our builds compile without external dependencies. `protox` helps achieve this. Signed-off-by: John Howard <john.howard@solo.io> * protobuf: move from openmetrics to protobuf Signed-off-by: John Howard <john.howard@solo.io> * Update changelog Signed-off-by: John Howard <john.howard@solo.io> * Bring back legacy proto Signed-off-by: John Howard <john.howard@solo.io> * Retain old 'protobuf' feature, make explicit types Signed-off-by: John Howard <john.howard@solo.io> --------- Signed-off-by: John Howard <john.howard@solo.io>

Commit:ffc2ab6
Author:Akihito Nakano
Committer:GitHub

encoding/: Add Protobuf support (#83) Add support for the OpenMetrics Protobuf encoding. Co-authored-by: Max Inden <mail@max-inden.de> Co-authored-by: Diva M <divma@protonmail.com>

The documentation is generated from this commit.

Commit:ead464c
Author:Max Inden
Committer:Max Inden

src/encoding: Remove proto support Remove proto scaffolding for now. Once Open Metrics proto format stabilized this commit can be reverted and proto support fully implemented.

This commit does not contain any .proto files.

Commit:a979df1
Author:Max Inden
Committer:Max Inden

src: Add proof-of-concept for proto encoding

Commit:2fb7983
Author:Max Inden

*: Add scaffolding for protobuf support