Add note to LFS and Create owns the priotization/implementation

Why is this change being made?

This MR adds a note to clarify that although the Package Group owns the marketing category for GitLFS, the prioritization and implementation of features is owned by the Source Code management group. Ultimately the Gitaly and Source Code groups are working to make Git LFS completely unnecessary by making Git better for large files, be they binary or plain text.

Background

In January 2020, we made a change to add Jupyter Notebooks and Git LFS categories to the Package stage. This was done as per gitlab-org/gitlab#55372 (closed) and gitlab-org/gitlab#55362 (closed) with the goal being to track both of these features as marketing categories.

• For Jupyter, which doesn't create much work, we decided to leave it as a marketing-only category owned by the Package Group. - For LFS, the marketing-category falls under the Package Group. But, the features prioritization and development falls under the Source Code Management category.

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][transparency]
• 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][mr-buddies-slack].
  • 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.