adding workflow for major release doc updates

[anaxceron]

Describe your pull request here: Documenting the process for updating doc for a major Zowe release

List the file(s) included in this PR: major_release_workflow.md

After creating the PR, follow the instructions in the comments.

[github-actions[bot]]

:smiley_cat: Thank you for creating this PR! To publish your content to Zowe Docs, follow these steps.

• [ ] Add the label review: sme if an SME needs to check your content.
• [ ] Identify your content topic with a label. (Examples: area: apiml, area: cli, area: install and config, etc.)
• [ ] Specify the major Zowe release(s) for your content. (Examples: release: V1, release: V2, release: V3)
  • [ ] If adding content that needs to be removed from V3 documentation, add the V3 N/A tag.
• [ ] Link any Doc Issues related to this PR.
• [ ] Fix broken links found in your content areas.
• [ ] Notify the SME to review this PR (if applicable).
• [ ] Merge to the master branch if your PR updates content that is on the live site. Merge to docs-staging if your PR updates content for a future release.

[github-actions[bot]]

:smiley_cat: Thank you for creating this PR! To publish your content to Zowe Docs, follow these steps.

• [ ] Add the label review: sme if an SME needs to check your content.
• [ ] Identify your content topic with a label. (Examples: area: apiml, area: cli, area: install and config, etc.)
• [ ] Specify the major Zowe release(s) for your content. (Examples: release: V1, release: V2, release: V3)
  • [ ] If adding content that needs to be removed from V3 documentation, add the V3 N/A tag.
• [ ] Link any Doc Issues related to this PR.
• [ ] Fix broken links found in your content areas.
• [ ] Notify the SME to review this PR (if applicable).
• [ ] Merge to the master branch if your PR updates content that is on the live site. Merge to docs-staging if your PR updates content for a future release.

[github-actions[bot]]

🚀 Deployed on https://673cec8d12517858f37e5e30--zowe-docs-master.netlify.app