Add grafana example

[keuhdall]

Added Grafana example as described in #270

I was planning to also add Loki for a full Grafana-stack example with log correlations, but I think it is currently blocked by #202
Let me know if I should change anything the example ! 🙂

[iRevive]

This example uses Scala 3. Should we reference the Scala version in the settings too?

[iRevive]

I also thinking about whether we should provide multiple examples:

1. sbt. Scala 2
2. sbt. Scala 3
3. scala-cli. Scala 2
4. scala-cli. Scala 3

The code will be nearly identical, so the benefit is questionable.

WDYT?

[keuhdall]

Regarding showing the differences between Scala 2 and 3 the only thing coming to my mind for sbt is ThisBuild / scalaVersion, maybe I'm missing something though. Assuming there's only this attribute changing I don't know if it's worth adding a dedicated scala 3 example just for that.
I never got to try scala-cli yet, so I can't really tell how different things should be there, so maybe it could be worth having a scala 3 example here, tell me what you think

[iRevive]

I don't see an entry point in the example above, so will sbt run work?

[keuhdall]

Just tried it on my example project, works fine 👌
On a second thought though I wonder if the scala-cli snippet makes a lot of sense here, it could maybe even be somewhat misleading as I chose grafana.scala kind of as a placeholder name.
Should I change/remove it ?

[iRevive]

Great example, thanks! I like dashboards being attached too. A few minor questions to discuss and we can move forward.

[iRevive]

Suggested change

	@:choice(scala-cli Scala 2)
	Add directives to the `grafana.scala`:
	```scala
	//> using lib "org.typelevel::otel4s-java:@VERSION@" // <1>
	//> using lib "io.opentelemetry:opentelemetry-exporter-otlp:@OPEN_TELEMETRY_VERSION@" // <2>
	//> using lib "io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:@OPEN_TELEMETRY_VERSION@" // <3>
	//> using `java-opt` "-Dotel.java.global-autoconfigure.enabled=true" // <4>
	//> using `java-opt` "-Dotel.service.name=grafana-example" // <5>
	```
	@:choice(scala-cli Scala 3)
	@:choice(scala-cli)

Let's keep only one scala-cli example.

[iRevive]

Suggested change

	//> using lib "org.typelevel::otel4s-java:@VERSION@" // <1>
	//> using scala 3.3.0
	//> using lib "org.typelevel::otel4s-java:@VERSION@" // <1>

That way we can ensure users will have a correct Scala version and the example will compile

[iRevive]

Suggested change

	@:choice(sbt Scala 3)
	Add settings to the `build.sbt`:
	```scala
	libraryDependencies ++= Seq(
	"org.typelevel" %% "otel4s-java" % "@VERSION@", // <1>
	"io.opentelemetry" % "opentelemetry-exporter-otlp" % "@OPEN_TELEMETRY_VERSION@" % Runtime, // <2>
	"io.opentelemetry" % "opentelemetry-sdk-extension-autoconfigure" % "@OPEN_TELEMETRY_VERSION@" % Runtime // <3>
	)
	run / fork := true
	javaOptions += "-Dotel.java.global-autoconfigure.enabled=true" // <4>
	javaOptions += "-Dotel.service.name=grafana-example" // <5>
	```

Let's keep only one sbt example

[iRevive]

Suggested change

	@:choice(sbt Scala 2)
	@:choice(sbt)

[iRevive]

I'm sorry for the delay. As you mentioned, I guess it's not worth making a separate example per Scala version since they are nearly identical.

[keuhdall]

Should be good now 👍

[iRevive]

I made a few changes to the PR keuhdall#1. We will have a minimal working example right on the documentation page, while we also reference your complete project too

[iRevive]

Thanks for the contribution!