Make it clear that docker ps filter name accepts regular expressions

Problem description

Docker ps command filtering option allows using regular expressions in its name parameter, while by the docs by it seems only strings are allowed and that it:

matches on all or part of a container’s name

Problem location

• I saw a problem on the following URL: https://docs-stage.docker.com/engine/reference/commandline/ps/#name

Project version(s) affected

I already checked this on 19.03.11, where I have two identically prefixed containers:

• app
• app_stage

Here

docker ps -a --filter name=app

returns both, while:

docker ps -a --filter name=^app$ 

only returns the first one.

Suggestions for a fix

Clarify that, at least for the name filter option, a regular expression may be specified.
I learned that from this comment.

Start at the Docker Engine CLI reference section for the name filter: https://docs-stage.docker.com/engine/reference/commandline/ps/#name. Review the existing wording against the reported app and ^app$ examples. Done means the documentation clearly states that the name filter accepts regular expressions.