Rename the old environment variable page to link environment variables.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

docs/compose-file.md

@@ -903,7 +903,8 @@ It's more complicated if you're using particular configuration features:
             syslog-address: "tcp://192.168.0.42:123"
 
 -   `links` with environment variables: As documented in the
-    [environment variables reference](env.md), environment variables created by
+    [environment variables reference](link-env-deprecated.md), environment variables
+    created by
     links have been deprecated for some time. In the new Docker network system,
     they have been removed. You should either connect directly to the
     appropriate hostname or set the relevant environment variable yourself,

docs/link-env-deprecated.md

@@ -1,15 +1,16 @@
 <!--[metadata]>
 +++
-title = "Environment Variables Reference"
+title = "Link Environment Variables"
 description = "Compose CLI reference"
 keywords = ["fig, composition, compose, docker, orchestration, cli,  reference"]
+aliases = ["/compose/env"]
 [menu.main]
 parent="workw_compose"
 weight=89
 +++
 <![end-metadata]-->
 
-# Compose environment variables reference
+# Link environment variables reference
 
 > **Note:** Environment variables are no longer the recommended method for connecting to linked services. Instead, you should use the link name (by default, the name of the linked service) as the hostname to connect to. See the [docker-compose.yml documentation](compose-file.md#links) for details.
 >