Make excerpts optional in header overlay
Some posts and some header images don't lend themselves well to
displaying the excerpt in the overlay. Make this optional by
introducting a new boolean variable:
`page.header.show_overlay_excerpt`
Set it to implicitly default to `true` so existing users are unaffected by
testing explicitly for "!= false".
This can be enabled globally for a site by changing the default to `false`
in the local _config.yml, or per page by specifying the value in front
matter.
Document show_overlay_excerpt variable
* Add show_overlay_excerpt variable to the Header Overlay field documentation table.
Close#1429
- Refactor seo.html include and add `page.header.og_image` override
- DRY up handling of page images (`page.header.image`, `page.header.overlay_image`, `page.header.teaser`, and `site.og_image`).
- Allow page images to be set with `header.og_image` page variable in YAML Front Matter as per feature request in #1316.
- Add sample posts for testing `og_image` override
- Set author bio as site OpenGraph default image
- Document `page.header.og_image` OpenGraph override
- Update CHANGELOG and history
Close#1316
* Add jekyll-toc include
* Reduce whitespace generated by comments
* Add table of contents include to `single` layout
* Replace `toc` include with jekyll-toc enabled YAML Front Matter
* Update README
* Update table of contents documentation
- Revise `toc` helper include to mention that it will be deprecated in the next major version.
- Add documentation to `single` layout explaining how to enable table of contents on those pages.
* Update CHANGELOG and history
* Update LICENSE
Close#1222
* Add YIQ Color Contrast mixin
* Remove text underline from `.btn` links
* Move YIQ variables
* Simplify button classes using YIQ color contrast mixin
- DRY up button CSS using Sass list and YIQ color contrast mixin.
- Move `color` and `background-color` to new `btn--primary` class instead of assinging on the default class. Removes the need to override them.
* Add `.btn--primary` to buttons that just had `.btn`
* Apply changes to `/docs`
* Add `.btn--primary` class
* Update CHANGELOG and history
* Add sample form
* Abstract colors away into Sass variables for easier themeing
* Add "dark" skin
* Replace hardcoded color with SCSS variable
* Invert Font Awesome icons' colors in author sidebar and footer
* Add Sass changes to `/docs`
* Use primary button type instead of inverse
* Add missing `!default` on `$muted-text-color`
* Add `contrast` and `sunrise` skin colors
* Add `dirt` skin color
* Add `air` skin color option
* Add `mint` skin color
* Add `btn--primary` class to Submit Comment button
* Set skin to `default`
* Document skin color options
* Add note about skin SCSS import
Close#1208
Liquid does not allow parenthesis, remove them to fix Liquid Exception: Liquid syntax error "Expected dotdot but found pipe" in `tag-list.html` and `category-list.html`
Close#1223
The links to the various social networks include data from the post
(title and url) which can contain URL special characters. Pass each of
the generated URLs through Liquid's `url_encode` filter to build HTML
complaint URLs.
* Added support for an alt tag for the header image
This allows using page.header.image_description as the alt tag. It
will still default to site.title if unset.
* Added documentation
