Split parser/serializer docs (#4690)

plugins/serializers/json/README.md

@@ -0,0 +1,77 @@
+# JSON
+
+The `json` output data format converts metrics into JSON documents.
+
+### Configuration
+
+```toml
+[[outputs.file]]
+  ## Files to write to, "stdout" is a specially handled file.
+  files = ["stdout", "/tmp/metrics.out"]
+
+  ## Data format to output.
+  ## Each data format has its own unique set of configuration options, read
+  ## more about them here:
+  ## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md
+  data_format = "json"
+
+  ## The resolution to use for the metric timestamp.  Must be a duration string
+  ## such as "1ns", "1us", "1ms", "10ms", "1s".  Durations are truncated to
+  ## the power of 10 less than the specified units.
+  json_timestamp_units = "1s"
+```
+
+### Examples:
+
+Standard form:
+```json
+{
+    "fields": {
+        "field_1": 30,
+        "field_2": 4,
+        "field_N": 59,
+        "n_images": 660
+    },
+    "name": "docker",
+    "tags": {
+        "host": "raynor"
+    },
+    "timestamp": 1458229140
+}
+```
+
+When an output plugin needs to emit multiple metrics at one time, it may use
+the batch format.  The use of batch format is determined by the plugin,
+reference the documentation for the specific plugin.
+```json
+{
+    "metrics": [
+        {
+            "fields": {
+                "field_1": 30,
+                "field_2": 4,
+                "field_N": 59,
+                "n_images": 660
+            },
+            "name": "docker",
+            "tags": {
+                "host": "raynor"
+            },
+            "timestamp": 1458229140
+        },
+        {
+            "fields": {
+                "field_1": 30,
+                "field_2": 4,
+                "field_N": 59,
+                "n_images": 660
+            },
+            "name": "docker",
+            "tags": {
+                "host": "raynor"
+            },
+            "timestamp": 1458229140
+        }
+    ]
+}
+```