docs: update the contributing guide for a successful cli debugging

[shahramk64]

Description

What this PR does / why we need it:

Following the guidelines in the Contributing file to debug the cli scenario does not result in a successful run. It seems that it assumes that a default config file exists in a specific path, which is not correct. A config file should be created for the cli scenario and it should be provided as an argument in the sample launch.json.

Which issue(s) this PR fixes (optional, using fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when the PR gets merged):

Fixes #1717

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Helm Chart Change (any edit/addition/update that is necessary for changes merged to the main branch)
• This change requires a documentation update

How Has This Been Tested?

It was tested by updating launch.json with the proposed sample json blob, and downloading notation.crt and making config_cli.json point to the downloaded file as described in the updated guide. After that, debugging with vscode results in a successful verification report.

Checklist:

• Does the affected code have corresponding tests?
• Are the changes documented, not just with inline documentation, but also with conceptual documentation such as an overview of a new feature, or task-based documentation like a tutorial? Consider if this change should be announced on your project blog.
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have appropriate license header?

Post Merge Requirements

• MAINTAINERS: manually trigger the "Publish Package" workflow after merging any PR that indicates Helm Chart Change

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

see 10 files with indirect coverage changes

[binbin-li]

lgtm!

[susanshi]

LGTM. thanks!

[binbin-li]

Please start with docs instead of doc in the ttile.