Reword the docker-image description

Author: jtdor

README.md

@@ -73,8 +73,8 @@ Options to be passed to `dpkg-buildpackage`. See `man dpkg-buildpackage`.
 Optional and empty by default.
 
 #### `docker-image`
-Name of a (Debian-based) Docker image to build packages inside or path of a
-Dockerfile in GITHUB_WORKSPACE to build a container from.
+Name of a Debian-based Docker image to use as build container or path of a
+Dockerfile in the workspace to build a temporary container from.
 
 Defaults to `debian:stable-slim`.
 

action.yml

@@ -18,7 +18,7 @@ inputs:
     required: false
   docker-image:
     default: debian:stable-slim
-    description: Name of a Docker image to build inside or path of a Dockerfile
+    description: Name of a Docker image or path of a Dockerfile to use for the build container
     required: true
   extra-build-deps:
     description: Extra packages to be installed as build dependencies