Improve README to explain tool usage

[micahlee]

Desired Outcome

The desired outcome of this PR is to add sufficient information to the README to allow successful execution of the tool for validating a Conjur container host machine.

Implemented Changes

This PR expands the usage and installation instructions, as well as details for inspecting disk performance.

Connected Issue/Story

CyberArk internal issue ID: CNJR-484

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be merged.

Changelog

• [ ] The CHANGELOG has been updated, or
• [x] 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

• [x] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: [insert issue ID]
• [ ] 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 ee17833a and detected 8 issues on this pull request.

Here's the issue category breakdown:

Category	Count
Style	8

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 94.2% (0.0% change).

View more on Code Climate.