doc: fix middleware names for CRD.

docs/content/middlewares/compress.md

@@ -15,6 +15,16 @@ labels:
 - "traefik.http.middlewares.test-compress.compress=true"
 ```
 
+```yaml tab="Kubernetes"
+# Enable gzip compression
+apiVersion: traefik.containo.us/v1alpha1
+kind: Middleware
+metadata:
+  name: test-compress
+spec:
+  compress: {}
+```
+
 ```json tab="Marathon"
 "labels": {
   "traefik.http.middlewares.test-compress.compress": "true"

docs/content/middlewares/stripprefix.md

@@ -22,7 +22,7 @@ kind: Middleware
 metadata:
   name: test-stripprefix
 spec:
-  StripPrefix:
+  stripPrefix:
     prefixes:
     - /foobar
     - /fiibar

docs/content/middlewares/stripprefixregex.md

@@ -22,7 +22,7 @@ kind: Middleware
 metadata:
   name: test-stripprefixregex
 spec:
-  StripPrefixRegex:
+  stripPrefixRegex:
     regex: "^/foo/(.*)"
 ```