[docs] Add example tracing infrastructure (#1866)

This adds an example on how to get Grafana Tempo up to receive spans as
well as Grafana itself to view them.

I've added this as a separate Tracing doc in the installation guide as
the Advanced one was starting to get rather full.

Fixes: #1791

example/tracing/docker-compose.yaml

@@ -0,0 +1,24 @@
+version: "3"
+services:
+  tempo:
+    image: docker.io/grafana/tempo:2.1.1
+    command: [ "-config.file=/etc/tempo.yaml" ]
+    volumes:
+      - ./tempo.yaml:/etc/tempo.yaml
+      - ./tempo-data:/tmp/tempo
+    ports:
+      - "3200:3200"  # tempo
+      - "9095:9095"  # tempo grpc
+      - "4317:4317"  # otlp grpc
+
+  grafana:
+    image: docker.io/grafana/grafana:9.5.2
+    volumes:
+      - ./grafana-datasources.yaml:/etc/grafana/provisioning/datasources/datasources.yaml
+    environment:
+      - GF_AUTH_ANONYMOUS_ENABLED=true
+      - GF_AUTH_ANONYMOUS_ORG_ROLE=Admin
+      - GF_AUTH_DISABLE_LOGIN_FORM=true
+      - GF_FEATURE_TOGGLES_ENABLE=traceqlEditor
+    ports:
+      - "3000:3000"

example/tracing/grafana-datasources.yaml

@@ -0,0 +1,16 @@
+apiVersion: 1
+
+datasources:
+- name: Tempo
+  type: tempo
+  access: proxy
+  orgId: 1
+  url: http://tempo:3200
+  basicAuth: false
+  isDefault: true
+  version: 1
+  editable: false
+  apiVersion: 1
+  uid: tempo
+  jsonData:
+    httpMethod: GET

example/tracing/tempo.yaml

@@ -0,0 +1,23 @@
+server:
+  http_listen_port: 3200
+
+distributor:
+  receivers:
+    otlp:
+      protocols:
+        grpc:
+
+ingester:
+  max_block_duration: 5m
+
+compactor:
+  compaction:
+    block_retention: 1h
+
+storage:
+  trace:
+    backend: local
+    wal:
+      path: /tmp/tempo/wal
+    local:
+      path: /tmp/tempo/blocks