Update the middleware documentation

docs/content/middlewares/retry.md

@@ -1,20 +1,48 @@
-# TODO -- Retry
+# Retry
 
 Retrying until it Succeeds
 {: .subtitle }
 
-## Old Content
+`TODO: add schema`
 
-## Retry Configuration
+Retry to send request on attempt failure.
 
-```toml
-# Enable retry sending request if network error
-[retry]
+## Configuration Examples
 
-# Number of attempts
-#
-# Optional
-# Default: (number servers in backend) -1
-#
-# attempts = 3
+```yaml tab="Docker"
+# Retry to send request 4 times
+labels:
+- "traefik.http.middlewares.test-retry.retry.attempts=4"
 ```
+
+```yaml tab="Kubernetes"
+# Retry to send request 4 times
+apiVersion: traefik.containo.us/v1alpha1
+kind: Middleware
+metadata:
+  name: test-retry
+spec:
+  retry:
+    attempts: 4
+```
+
+```yaml tab="Rancher"
+# Retry to send request 4 times
+labels:
+- "traefik.http.middlewares.test-retry.retry.attempts=4"
+```
+
+```toml tab="File"
+# Retry to send request 4 times
+[http.middlewares]
+  [http.middlewares.test-retry.Retry]
+     attempts = 4
+```
+
+## Configuration Options
+
+### `attempts` 
+
+_mandatory_
+
+The `attempts` option defines how many times to try sending the request.