Merge pull request #4773 from wrfly/patch-1

Not a colon but a dot.

README.md

@@ -17,7 +17,7 @@ Using Compose is basically a three-step process.
 1. Define your app's environment with a `Dockerfile` so it can be
 reproduced anywhere.
 2. Define the services that make up your app in `docker-compose.yml` so
-they can be run together in an isolated environment:
+they can be run together in an isolated environment.
 3. Lastly, run `docker-compose up` and Compose will start and run your entire app.
 
 A `docker-compose.yml` looks like this: