added note about shorter command 'docker build'

[thadguidry]

- What I did
Documentation Improvement

- How I did it
This will help clarify to users that they are the same command.
As well as make it clear in the auto-generated docs https://docs.docker.com/engine/reference/commandline/image_build/

- How to verify it

- Description for the changelog
Added note to 'docker image build' about shorter syntax 'docker build'

[GordonTheTurtle]

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "patch-1" git@github.com:thadguidry/cli.git somewhere
$ cd somewhere
$ git commit --amend -s --no-edit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[codecov-io]

Codecov Report

Merging #1703 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1703   +/-   ##
=======================================
  Coverage   56.12%   56.12%           
=======================================
  Files         306      306           
  Lines       21030    21030           
=======================================
  Hits        11803    11803           
  Misses       8373     8373           
  Partials      854      854

[tiborvass]

Thank you for your contribution but this is not specific to build, so we'd need to either make it consistent across all aliased commands or decide not to take it, sorry!

[thadguidry]

That's unfortunate because it was a question asked by 3 independent Ericsson developers towards our Devops group and I had to explain this to them and puzzled why they didn't know...they said... "their docs really didn't explain that well, thanks for explaining to us Thad."

[tiborvass]

@thadguidry I'm not against clarifying that if that's confusing. I just think other commands need the same adjustments "docker container run==docker run` etc. Also, you are modifying the help output within the documentation, but not the help output in the code itself. If you need help let us know.

[adeniyistephen]

@tiborvass @thaJeztah As the documentation be updated yet? Can i work on this i would love to kindly provide input or pointers.

[thaJeztah]

This example shows the output how the CLI itself prints it, which does not include this).

We added additional metadata, and usage output in these PR's though (and will be using those in the documentation);

• cli: print full command as aliases in usage output #3693
• cli: use custom annotation for aliases #3694

[thaJeztah]

closing this per above, but thanks for contributing!