Make command help more consistent

[szh]

Desired Outcome

Short / Long Descriptions for CLI commands were created mostly ad-hoc with an evolving style as we implemented more commands. Go back over them and rework for consistency.

Implemented Changes

Updated short and long descriptions for several commands to improve consistency and clarity.

Connected Issue/Story

CyberArk internal issue ID: CNJR-276

Changelog

• [x] The CHANGELOG has been updated, or
• [ ] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [x] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: [insert issue ID]
• [x] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [x] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [x] There are no security aspects to these changes

[codeclimate[bot]]

Code Climate has analyzed commit 07018221 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 81.5% (0.0% change).

View more on Code Climate.