* Fix absolute URL generation
url and baseurl config for this theme deviates from jekyll standard,
and that results in double inclusion of project path
if this theme is used as project page.
Switching to Jekyll accepted url usage so that
absolute_url filter works.
* Alternate links need to be aboslute
* mention url and baseurl only need to be modified in local dev
* Update readme on new url/baseurl setting changes
* remove tag _gen plugin and its folder
* remove deprecated tag index layout
* add tag index page
* link tag index page in nav bar, enable tag links by default
* add button spacer in main css
* fix tag links in post view
* fix tag links on index and pagination
* tag link instuctions removed. it's enabled as default
