Markdown pages improvements

[bri25yu]

• https://dev-hkn.eecs.berkeley.edu/pages/ is open to the public
• improve https://dev-hkn.eecs.berkeley.edu/pages/ display
• list markdown pages creation and editing on main site somehow (and lead users to that interface)
• Add serv and indrel pages as customizable markdown pages instead of hardcoded html (this also goes for other templates with the same pattern)