add span id to example

Author: chargome

develop-docs/sdk/telemetry/metrics.mdx

@@ -477,6 +477,7 @@ If `debug` is set to `true` in SDK init, calls to the Sentry metrics API should
     {
       "timestamp": 1746456149.019,
       "trace_id": "624f66e93a04469f9992c7e9f1485056",
+      "span_id": "b0e6f15b45c36b12",
       "name": "api.requests",
       "value": 1,
       "type": "counter",
@@ -493,6 +494,7 @@ If `debug` is set to `true` in SDK init, calls to the Sentry metrics API should
     {
       "timestamp": 1746456149.019,
       "trace_id": "624f66e93a04469f9992c7e9f1485056",
+      "span_id": "b0e6f15b45c36b12",
       "name": "api.response_time",
       "value": 125.5,
       "unit": "millisecond",
@@ -507,6 +509,7 @@ If `debug` is set to `true` in SDK init, calls to the Sentry metrics API should
     {
       "timestamp": 1746456149.02,
       "trace_id": "624f66e93a04469f9992c7e9f1485056",
+      "span_id": "b0e6f15b45c36b12",
       "name": "cache.hit_rate",
       "value": 0.95,
       "unit": "ratio",
@@ -521,6 +524,7 @@ If `debug` is set to `true` in SDK init, calls to the Sentry metrics API should
     {
       "timestamp": 1746456149.02,
       "trace_id": "624f66e93a04469f9992c7e9f1485056",
+      "span_id": "b0e6f15b45c36b12",
       "name": "database.query.duration",
       "value": 42.3,
       "unit": "millisecond",
@@ -536,6 +540,7 @@ If `debug` is set to `true` in SDK init, calls to the Sentry metrics API should
     {
       "timestamp": 1746456149.021,
       "trace_id": "624f66e93a04469f9992c7e9f1485056",
+      "span_id": "b0e6f15b45c36b12",
       "name": "active.users",
       "value": 12345,
       "type": "set",