Fix a typo: change "such Bash" to "such as Bash"

Signed-off-by: Anatoly Borodin <anatoly.borodin@gmail.com>

docs/articles/dockerfile_best-practices.md

@@ -382,7 +382,7 @@ Or, it can be used to run Postgres and pass parameters to the server:
 
     $ docker run postgres postgres --help
 
-Lastly, it could also be used to start a totally different tool, such Bash:
+Lastly, it could also be used to start a totally different tool, such as Bash:
 
     $ docker run --rm -it postgres bash