Update README.md

README.md

@@ -2,7 +2,7 @@
 
 This is an example of a Docker image that bootstraps an internal CA.
 It can serve as a pattern for trusting internal CAs, for any Ubuntu-based Docker image.
-The CA URL and Fingerprint can be hardcoded or supplied as build arguments.
+The CA URL and Fingerprint can be hardcoded in the `Dockerfile` or supplied as build arguments.
 
 This image can be layered on top of any Ubuntu-based server image.
 For example, change `FROM ubuntu:focal` to `FROM mongo` and you will get a MongoDB server that trusts your CA.