add datadog API docs

Signed-off-by: Bojan <dbojan@gmail.com>

docs/crd.md

@@ -237,6 +237,7 @@ OutputSpec defines the desired state of Output
 | tcp | TCP defines TCP Output configuration. | *[output.TCP](plugins/output/tcp.md) |
 | loki | Loki defines Loki Output configuration. | *[output.Loki](plugins/output/loki.md) |
 | syslog | Syslog defines Syslog Output configuration. | *[output.Syslog](plugins/output/syslog.md) |
+| datadog | DataDog defines DataDog Output configuration. | *[output.DataDog](plugins/output/datadog.md) |
 
 [Back to TOC](#table-of-contents)
 ## Parser

docs/plugins/output/datadog.md

@@ -0,0 +1,20 @@
+# Syslog
+
+DataDog output plugin allows you to ingest your logs into Datadog.
+
+| Field | Description | Scheme |
+| ----- | ----------- | ------ |
+| host |  Host is the Datadog server where you are sending your logs. | string |
+| tls | Datadog recommends setting this to on. | bool |
+| compress | Compress the payload in GZIP format. Datadog supports and recommends setting this to gzip. | string |
+| apikey | Your Datadog API key. | string |
+| proxy | Specify an HTTP Proxy. | string |
+| provider | To activate the remapping, specify configuration flag provider. | string |
+| json_date_key | Date key name for output. | string |
+| include_tag_key | If enabled, a tag is appended to output. The key name is used tag_key property. | bool |
+| tag_key | The key name of tag. If include_tag_key is false, This property is ignored. | string |
+| dd_service | The human readable name for your service generating the logs. | string |
+| dd_source | A human readable name for the underlying technology of your service. | string |
+| dd_tags | The tags you want to assign to your logs in Datadog. | string |
+| dd_message_key |By default, the plugin searches for the key 'log' and remap the value to the key 'message'. If the property is set, the plugin will search the property name key. | string |
+