docs: update rate limiting

docs/middleware/rate-limit.md

@@ -10,13 +10,35 @@ nav_order: 6
 
 The RateLimit middleware ensures that services will receive a fair number of requests, and allows one to define what fair is.
 
-Example of global rateLimit middleware
+Example of rate limiting middleware
+
+```yaml
+middlewares:
+  - name: rate-limit
+    type: ratelimit #or rateLimit
+    paths:
+      - /*
+    rule:
+      unit: minute # or hour
+      requestsPerUnit: 10
+```
+
+Example of route rate limiting middleware
+
+```yaml
+version: 0.1.7
+gateway:
+  routes:
+    - name: Example
+      rateLimit: 60 # peer minute
+```
+
+Example of global rate limiting middleware
 
 ```yaml
 version: 0.1.7
 gateway:
-  # Proxy rate limit, it's In-Memory IP based
   rateLimit: 60 # peer minute
   routes:
     - name: Example
-```
+```