Allow almost all printable ASCII characters in environment variables

Author: HirazawaUi

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

@@ -41,7 +41,7 @@ In this exercise, you create a Pod that runs one container. The configuration
 file for the Pod defines an environment variable with name `DEMO_GREETING` and
 value `"Hello from the environment"`. Here is the configuration manifest for the
 Pod:
-
+placeholder
 {{% code_sample file="pods/inject/envars.yaml" %}}
 
 1. Create a Pod based on that manifest: