cut out header section to put into header.html and wrote in liquid templating code to include header.html
created header.html and filled with content from default template to ensure consistency of these elements across site
removed content from default template and placed it in footer.html to ensure consistency of this content across site
added / in front of link to side menu css to resolve issue where menu didn't load correctly on individual post pages
removed extraneous div#main that I had added trying to fix issue with non-showing menu