Fix spelling of delimited

Signed-off-by: Nick Adcock <nick.adcock@docker.com>

README.md

@@ -102,7 +102,7 @@ Always attempt to pull a newer version of the image.
 
 ### `build_args`
 
-Comma-delmited list of build-time variables.
+Comma-delimited list of build-time variables.
 
 Example:
 

action.yml

@@ -45,7 +45,7 @@ inputs:
     required: false
     default: false
   build_args:
-    description: Comma-delmited list of build-time variables
+    description: Comma-delimited list of build-time variables
     required: false
   labels:
     description: Comma-delimited list of labels to add to the built image