Typo in annotations.md (#119)

Author: jakaruna-MSFT

docs/annotations.md

@@ -15,7 +15,7 @@ appgw.ingress.kubernetes.io/backend-path-prefix: <path prefix>
 
 ### Example
 ```yaml
-piVersion: extensions/v1beta1
+apiVersion: extensions/v1beta1
 kind: Ingress
 metadata:
   name: go-server-ingress-bkprefix
@@ -34,4 +34,4 @@ spec:
 ```
 In the example above we have defined an ingress resource named `go-server-ingress-bkprefix` with an annotation `appgw.ingress.kubernetes.io/backend-path-prefix: "/test/"` . The annotation tells application gateway to create an HTTP setting which will have a path prefix override for the path `/hello` to `/test/`. 
 
-***NOTE:*** In the above example we have only one rule defined. However, the annotations is applicable to the entire ingress resource so if a user had defined multiple rules the backend path prefix would be setup for each of the paths sepcified. Thus, if a user wants different rules with different path prefixes (even for the same service) they would need to define different ingress resources. 
+***NOTE:*** In the above example we have only one rule defined. However, the annotations is applicable to the entire ingress resource so if a user had defined multiple rules the backend path prefix would be setup for each of the paths sepcified. Thus, if a user wants different rules with different path prefixes (even for the same service) they would need to define different ingress resources.