Move topic to Injecting Data section. (#3622)

* Move topic to Injecting Data section.

* Move included file.

_data/tasks.yml

@@ -13,7 +13,6 @@ toc:
 
 - title: Configuring Pods and Containers
   section:
-  - docs/tasks/configure-pod-container/define-environment-variable-container.md
   - docs/tasks/configure-pod-container/define-command-argument-container.md
   - docs/tasks/configure-pod-container/assign-cpu-ram-container.md
   - docs/tasks/configure-pod-container/limit-range.md
@@ -39,6 +38,10 @@ toc:
   - docs/tasks/configure-pod-container/weave-network-policy.md
   - docs/tools/kompose/user-guide.md
 
+- title: Injecting Data Into Applications
+  section:
+  - docs/tasks/inject-data-application/define-environment-variable-container.md
+
 - title: Running Applications
   section:
   - docs/tasks/run-application/rolling-update-replication-controller.md

docs/tasks/inject-data-application/define-environment-variable-container.md

@@ -1,5 +1,8 @@
 ---
 title: Defining Environment Variables for a Container
+redirect_from:
+- "/docs/tasks/configure-pod-container/define-environment-variable-container/"
+- "/docs/tasks/configure-pod-container/define-environment-variable-container.html"
 ---
 
 {% capture overview %}
@@ -30,7 +33,7 @@ file for the Pod defines an environment variable with name `DEMO_GREETING` and
 value `"Hello from the environment"`. Here is the configuration file for the
 Pod:
 
-{% include code.html language="yaml" file="envars.yaml" ghlink="/docs/tasks/configure-pod-container/envars.yaml" %}
+{% include code.html language="yaml" file="envars.yaml" ghlink="/docs/tasks/inject-data-application/envars.yaml" %}
 
 1. Create a Pod based on the YAML configuration file: