Update Chapter 1: COBOL Programming Course #1 - Getting Started to Zowe V3

[Rituraj-M50]

Proposed changes

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context to communicate to the maintainers why we should accept this pull request.

Fixes # (issue)

This pull request includes the following changes:

1. Updated the main course markdown file.
2. Detailed unnecessary files from images.
3. Updates images in course materials.

Type of change

What type of changes does your PR introduce to the COBOL Programming Course? Put an x in the boxes that apply.

• Bug fix (change which fixes one or more issues)
• New feature (change which adds functionality or features to the course)
• Translations (change which adds or modifies translations of the course)
• Documentation (change which modifies documentation related to the course)
• This change requires an update to the course's z/OS environment

Checklist:

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• I have read the Contributing Guideline
• I have included a title and description for this PR
• I have DCO-signed all of my commits that are included in this PR
• I have tested it manually and there are no regressions found
• I have commented my code, particularly in hard-to-understand areas (if appropriate)
• I have made corresponding changes to the documentation (if appropriate)

[tanto259]

Hi Rituraj,

Thank you for your contributions! Left some comments on the change, but overall, it looks good to me.