keptn docs added (#252)

docs/configuration/source/keptn.md

@@ -0,0 +1,37 @@
+---
+id: keptn
+title: Keptn
+sidebar_position: 4
+---
+
+The Botkube Keptn source plugin allows you to consume events from Keptn deployment and notify in configured platforms.
+
+The Keptn plugin is hosted by the official Botkube plugin repository. To enable the Keptn plugin, make sure that the `botkube` repository is defined under `plugins` in the [values.yaml](https://github.com/kubeshop/botkube/blob/main/helm/botkube/values.yaml) file.
+
+```yaml
+plugins:
+  repositories:
+    botkube:
+      url: https://github.com/kubeshop/botkube/releases/download/v1.2.0/plugins-index.yaml
+```
+
+## Enabling plugin
+
+To enable Keptn plugin, add `--set 'sources.keptn.botkube/keptn.enabled=true'` to a given Botkube [`install` command](../../cli/commands/botkube_install.md).
+
+## Syntax
+
+```yaml
+# Map of sources. The `sources` property name is an alias for a given configuration.
+# Key name is used as a binding reference.
+#
+# Format: sources.{alias}
+sources:
+  "keptn":
+    botkube/keptn: # Plugin name syntax: <repo>/<plugin>[@<version>]. If version is not provided, the latest version from repository is used.
+      enabled: true # If not enabled, plugin is not downloaded and started.
+      config: # Plugin's specific configuration.
+        project: "" # Keptn project name
+        url: "http://api-gateway-nginx.keptn" # Keptn API Gateway to fetch events.
+        token: "" # Keptn API Token to authenticate API Gateway to fetch events.
+```

docs/usage/source/keptn.md

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+---
+id: keptn
+title: "Keptn"
+sidebar_position: 4
+---
+
+Botkube allows you to consume `keptn` events on your Kubernetes cluster. By default, `keptn` plugin is disabled. See the [**Enabling plugin**](../../configuration/source/keptn#enabling-plugin) section from the `keptn` configuration documentation.
+
+Once it is enabled, Botkube Keptn plugin will consume Keptn events and send them to configured platforms as shown below.
+
+![Keptn Events](./assets/keptn-events.png)