How to: Prometheus code base
In order to comply with [go mod](https://go.dev/ref/mod#versions) rules,
Prometheus release number do not exactly match Go module releases.

For the
Prometheus v3.y.z releases, we are publishing equivalent v0.3y.z tags. The y in v0.3y.z is always padded to two digits, with a leading zero if needed.

Therefore, a user that would want to use Prometheus v3.0.0 as a library could do:

```shell
go get github.com/prometheus/prometheus@v0.300.0
```

For the
Prometheus v2.y.z releases, we published the equivalent v0.y.z tags.

Therefore, a user that would want to use Prometheus v2.35.0 as a library could do:

```shell
go get github.com/prometheus/prometheus@v0.35.0
```

This solution makes it clear that we might break our internal Go APIs between
minor user-facing releases, as [breaking changes are allowed in major version
zero](https://semver.org/#spec-item-4).