Add docs for new bot resource

docs/pages/includes/machine-id/bot-spec.mdx

@@ -0,0 +1,19 @@
+```yaml
+kind: bot
+version: v1
+metadata:
+  # name is a unique identifier for the bot in the cluster.
+  name: robot
+spec:
+  # roles is a list of roles that the bot should be able to generate credentials
+  # for.
+  roles:
+  - editor
+  # traits controls the traits applied to the Bot user. These are fed into the
+  # role templating system and can be used to grant a specific Bot access to
+  # specific resources without the creation of a new role.
+  traits:
+  - name: logins
+    values:
+    - root
+```

docs/pages/machine-id/reference/configuration.mdx

@@ -388,3 +388,13 @@ type: kubernetes_secret
 # This must be in the same namespace that `tbot` is running in.
 name: my-secret
 ```
+
+## Bot resource
+
+The `bot` resource is used to manage Machine ID Bots. It is used to configure
+the access that is granted to a Bot.
+
+(!docs/pages/includes/machine-id/bot-spec.mdx!)
+
+You can apply a file containing YAML that defines a `bot` resource using
+`tctl apply -f ./bot.yaml`.

docs/pages/reference/resources.mdx

@@ -252,3 +252,12 @@ spec:
 
 version: v2
 ```
+
+## Bot
+
+Bot resources define a Machine ID Bot identity and its access.
+
+Find out more on the
+[Machine ID configuration reference](../machine-id/reference/configuration.mdx).
+
+(!docs/pages/includes/machine-id/bot-spec.mdx!)