Add new Style and Test Automation committees to Tech Writing Handbook

• Establishes Technical Writing Style Committee and Test Automation Committee.
• Adds Quality section to TW Handbook with a subsection for each committee.
• Adds members to "Assignments to other projects and subjects" table.
• Removes Style Guide from the existing Developer guidelines ownership.

Review app https://tw-style-testing-committees.about.gitlab-review.app/handbook/engineering/ux/technical-writing/index.html#quality

Why is this change being made?

Closes gitlab-org/technical-writing#109 (closed)

Next steps for each DRI

• Establish issue board
• Communicate change
• Schedule recurring calls with committee

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.

For help with failing pipelines reach out in #mr-buddies in Slack