[Erlang] Add Project Status table for each Signal in README top section

[trivikr]

Is your feature request related to a problem? Please describe.

The Project Status of Traces/Metrics/Logs Signals in OpenTelemetry is difficult to find in OpenTelemetry for Erlang.

Describe the solution you'd like Add Project Status Table at the top of README, similar to how it's done in other implementations:

• .NET https://github.com/open-telemetry/opentelemetry-dotnet
• Go https://github.com/open-telemetry/opentelemetry-go
• CPP https://github.com/open-telemetry/opentelemetry-cpp

The Status Table would list Signal and the current status

| Signal  | Status                            | Project                           |
| ------- | --------------------------------- | --------------------------------- |
| Traces  | Experimental/Alpha/Beta/RC/Stable | [version](link-to-github-project) |
| Metrics | Experimental/Alpha/Beta/RC/Stable | [version](link-to-github-project) |
| Logs    | Experimental/Alpha/Beta/RC/Stable | [version](link-to-github-project) |

Describe alternatives you've considered Going through repo contents to find the status of each Signal.

Additional context Summary table for OpenTelemetry Status https://github.com/open-telemetry/opentelemetry.io/issues/1548

[trivikr]

On a quick look at version numbers and GitHub projects, this is what I think the table is:

Signal	Status	Project
Traces	Stable	N/A
Metrics	Alpha	N/A
Logs	N/A	N/A

Based on https://opentelemetry.io/docs/instrumentation/erlang/ If it's incorrect, please provide the correct table in this GitHub issue, so that it can be updated on README.

[tsloughter]

Thanks. I'll get this added, unless you wanted to send a PR :)

[trivikr]

The consensus is being achieved towards treating website as authoritative, and provide a link to website instead.

https://github.com/open-telemetry/opentelemetry-java/pull/4612#issuecomment-1185118267

We'll request the status page to link to language instrumentation links instead of GitHub READMEs in https://github.com/open-telemetry/opentelemetry.io/issues/1548