Demonstrate how to set the Resource for LogEmitterProvider (#2209)

* Demonstrate how to set the Resource for LogEmitterProvider

Added a Resource to the logs example to make it more complete.
Previously it was using the built-in Resource. Now it adds the
service.name and service.instance.id attributes.

The resulting emitted log records look like this:
```
Resource labels:
     -> telemetry.sdk.language: STRING(python)
     -> telemetry.sdk.name: STRING(opentelemetry)
     -> telemetry.sdk.version: STRING(1.5.0)
     -> service.name: STRING(shoppingcart)
     -> service.instance.id: STRING(instance-12)
InstrumentationLibraryLogs #0
InstrumentationLibrary __main__ 0.1
LogRecord #0
Timestamp: 2021-10-14 18:33:43.425820928 +0000 UTC
Severity: ERROR
ShortName:
Body: Hyderabad, we have a major problem.
Trace ID: ce1577e4a703f42d569e72593ad71888
Span ID: f8908ac4258ceff6
Flags: 1
```

* Fix linting

docs/examples/logs/example.py

@@ -2,8 +2,13 @@
 
 from opentelemetry import trace
 from opentelemetry.exporter.otlp.proto.grpc.log_exporter import OTLPLogExporter
-from opentelemetry.sdk.logs import OTLPHandler, get_log_emitter_provider
+from opentelemetry.sdk.logs import (
+    LogEmitterProvider,
+    OTLPHandler,
+    set_log_emitter_provider,
+)
 from opentelemetry.sdk.logs.export import SimpleLogProcessor
+from opentelemetry.sdk.resources import Resource
 from opentelemetry.sdk.trace import TracerProvider
 from opentelemetry.sdk.trace.export import (
     ConsoleSpanExporter,
@@ -15,7 +20,16 @@
     SimpleSpanProcessor(ConsoleSpanExporter())
 )
 
-log_emitter_provider = get_log_emitter_provider()
+log_emitter_provider = LogEmitterProvider(
+    resource=Resource.create(
+        {
+            "service.name": "shoppingcart",
+            "service.instance.id": "instance-12",
+        }
+    ),
+)
+set_log_emitter_provider(log_emitter_provider)
+
 exporter = OTLPLogExporter(insecure=True)
 log_emitter_provider.add_log_processor(SimpleLogProcessor(exporter))
 log_emitter = log_emitter_provider.get_log_emitter(__name__, "0.1")