opentelemetry-proto 0.4.0

Protobuf generated files and transformations.
Documentation
# Changelog

## vNext

## v0.4.0

### Added

- Implement tonic metrics proto transformations (#1184)
- Move proto for zPage to tonic [#1214]https://github.com/open-telemetry/opentelemetry-rust/pull/1214
- Support exponential histograms (#1267)

### Changed

- Bump MSRV to 1.65 [#1318]https://github.com/open-telemetry/opentelemetry-rust/pull/1318
- Bump MSRV to 1.64 [#1203]https://github.com/open-telemetry/opentelemetry-rust/pull/1203

### Fixed

- Rename `traces` feature to the more standard `trace` (#1183)

### Changed

- Switch to `prost` for `grpcio` protos. (#1202)
  The `gen-protoc` feature is accordingly renamed to `gen-grpcio`.

## v0.3.0

### Updated

- Update protobuf definitions to v1.0.0 #1154
- Update to opentelemetry-api v0.20.0

## v0.2.0
### Changed
- Update to opentelemetry v0.19.0.
- Remove build script and generate files using unit tests [#881]https://github.com/open-telemetry/opentelemetry-rust/pull/881.
- Bump MSRV to 1.57 [#953]https://github.com/open-telemetry/opentelemetry-rust/pull/953.
- Update dependencies and bump MSRV to 1.60 [#969]https://github.com/open-telemetry/opentelemetry-rust/pull/969.
- Bump to use the v0.19.0 protobuf definitions. [#989]https://github.com/open-telemetry/opentelemetry-rust/pull/989.

## v0.1.0

Initial crate release.