Further improve markdown editor for project editing

[jugovimm]

After demoing the markdown editor for project full descriptions, there are some improvements that could be made:

• Remove functionality to add quotes
• Remove functionality to add links
• Add note message instructing users to add resource links in below section of metadata editing page
• Idea: if a user starts typing in a link regex like "..." then have note appear instructing them to add below
  • OR possible to disable formatting for links in editor and description?