docs: Add loki and datadog documentation

docs/docs.logflare.com/docs/backends/datadog.mdx

@@ -0,0 +1,24 @@
+---
+sidebar_position: 5
+---
+
+# Datadog
+
+The Datadog backend is **ingest-only**, and sends events to the Datadog HTTP API.
+
+See the Datadog HTTP API [documentation](https://docs.datadoghq.com/api/latest/logs/#send-logs) for details on how the API handles events.
+
+## Behaviour and configurations
+
+### Configuration
+
+The following values are required when creating a webhook backend:
+
+- `api_key`: (`string`, required) a API Key generated from the Datadog dashboard, specific for that region.
+- `region`: (`string`, required) specific region API to send the events to. Corresponds to the [Datadog sites](https://docs.datadoghq.com/getting_started/site/) (for example `US5`)
+
+### Implementation Details
+
+Implementation is based on the [webhook backend](/backends/webhook).
+
+Events will be gzipped and batch with a maximum of 250 events per request. The source name will be set as the service name.

docs/docs.logflare.com/docs/backends/loki.mdx

@@ -0,0 +1,26 @@
+---
+sidebar_position: 6
+---
+
+# Loki
+
+The Loki backend is **ingest-only**, and sends events to a Loki HTTP API.
+
+See the Loki HTTP API [documentation](https://grafana.com/docs/loki/latest/reference/loki-http-api/#ingest-logs) for details on how the API handles events.
+
+## Behaviour and configurations
+
+### Configuration
+
+The following values are required when creating a webhook backend:
+
+- `url`: (`string`, required) the HTTP url to send the events to.
+- `headers`: (`map`, optional) the headers to be attached to the HTTP request, for authentication purposes.
+
+### Implementation Details
+
+Implementation is based on the [webhook backend](/backends/webhook).
+
+Events will be gzipped as a JSON payload, and will be batched with a maximum of 250 events per request.
+
+The source name will be used as the stream label.