docs: fix tbd link and minor edits in deployment guide

[jenniferfell]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• [ X] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[X ] Documentation content changes
[ ] angular.io application / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Deployment guide (https://next.angular.io/guide/deployment) ends with a TBD link for the CLI reference.

Issue Number: N/A

What is the new behavior?

Deployment guide links to CLI overview page https://next.angular.io/cli

Minor edits for consistency, mostly to refer to CLI commands as ng serve not just serve.

Does this PR introduce a breaking change?

[ ] Yes
[X ] No

Other information

[mary-poppins]

You can preview ed08a41 at https://pr26404-ed08a41.ngbuilds.io/.

[ngbot]

I see that you just added the PR action: merge label, but the following checks are still failing:
     status "ci/circleci: integration_test" is failing
     status "continuous-integration/travis-ci/pr" is failing
     status "code-review/pullapprove" is pending

If you want your PR to be merged, it has to pass all the CI checks.

If you can't get the PR to a green state due to flakes or broken master, please try rebasing to master and/or restarting the CI job. If that fails and you believe that the issue is not due to your change, please contact the caretaker and ask for help.

[IgorMinar]

caretaker note: red ci is due to flakes.

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