Prepare CLI for homebrew release

Desired Outcome

The Conjur CLI is currently generating a homebrew .rb file upon release, but it hasn't yet been added to the https://github.com/cyberark/homebrew-tools repository so it remains unavailable for installation with homebrew. This PR simply updates the name of the generated .rb file from conjur-cli-go to conjur-cli and adds a step to the release documentation to update it in the homebrew-tools repo. Once this is merged, upon the next release of the CLI we can publish to homebrew.

Connected Issue/Story

CyberArk internal issue ID: CNJR-95

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

[x] 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
[ ] 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

cyberark / conjur-cli-go