fix(uma2): ref links

fix(uma2): correct UMA2 ref links

build(add partials for hugo): add partials

build(rss): enable gen xml file for rss

fix(uma2.md): image links

fix(post reference): fix post reference (fragment) not work with hugo…

… config canonifyurls=true

fix(index.json): revert change that use htmlEscape

revert previous change but use with printf

improvement(index.json): support ref in post description

fix(image url): update image urls

fix(image url): fix image url to match with new diagram dir