rename usage -> infra and fix a legacy doc link

Author: dormando

content/features/proxy/_index.md

@@ -93,6 +93,6 @@ In advanced use cases, you can modify the route library file, or even replace it
 
 ## Proxy deployment examples
 
-For a selection of example proxy use cases, see [Usage examples]({{<legacy_proxy_base_path>}}examples).
+For a selection of proxy infrastructure use cases, see [Infrastructure examples]({{<proxy_base_path>}}examples).
 
 For a example proxy configuration files, see [Example configuration files]({{<proxy_base_path>}}configure#examples).

content/features/proxy/examples.md

@@ -1,5 +1,5 @@
 +++
-title = 'Usage examples'
+title = 'Infrastructure examples'
 date = 2024-09-01T09:08:32-07:00
 weight = 50
 +++