* Creating Marketing division of the handbook
Marketing is comprised of Community, Digital Experience, Growth, and Handbook.
* Update marketing.md
* Update and rename handbook/company/marketing.md to handbook/marketing/README.md
* Update README.md
* Rename handbook/growth/README.md to handbook/marketing/growth.md
* Rename handbook/digital-experience/README.md to handbook/marketing/digital-experience.md
* Rename handbook/digital-experience/article-formatting-guide.md to handbook/marketing/article-formatting-guide.md
* Rename handbook/digital-experience/commonly-used-terms.md to handbook/marketing/commonly-used-terms.md
* Rename handbook/digital-experience/how-to-submit-and-publish-an-article.md to handbook/marketing/how-to-submit-and-publish-an-article.md
* Rename handbook/digital-experience/markdown-guide.md to handbook/marketing/markdown-guide.md
* Rename handbook/community/README.md to handbook/marketing/community.md
* Update markdown-guide.md
Co-authored-by: Mike McNeil <mikermcneil@users.noreply.github.com>
