add documentation and correct a bug

Author: aleksclark

README.md

@@ -99,6 +99,10 @@ Example: `"0/100"`
 
 The region we deploy the ECS Service to.
 
+### `env` (optional)
+
+An array of environment variables to add to *every* image's task definition
+
 ## AWS Roles
 
 At a minimum this plugin requires the following AWS permissions to be granted to the agent running this step:

hooks/command

@@ -126,8 +126,6 @@ done
 ## This adds the env vars to each container
 image_idx=0
 for image in "${images[@]}"; do
-  container_definitions_json=$(echo "$container_definitions_json" | jq ".[${image_idx}].environment=[]"
-  )
   for env_var in "${env_vars[@]}"; do
     # shellcheck disable=SC2206
     var_val=(${env_var//=/ })