Merge pull request #1977 from J0WI/update-alpine-example

Update Alpine example

alpine/content.md

@@ -11,7 +11,7 @@
 Use like you would any other base image:
 
 ```dockerfile
-FROM %%IMAGE%%:3.7
+FROM %%IMAGE%%:3.14
 RUN apk add --no-cache mysql-client
 ENTRYPOINT ["mysql"]
 ```
@@ -19,7 +19,7 @@ ENTRYPOINT ["mysql"]
 This example has a virtual image size of only 36.8MB. Compare that to our good friend Ubuntu:
 
 ```dockerfile
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 RUN apt-get update \
     && apt-get install -y --no-install-recommends mysql-client \
     && rm -rf /var/lib/apt/lists/*