* add integrity hash for Font Awesome script
As the script is loaded from an external CDN (use.fontawesome.com), its integrity must be ensured mainly for security reasons.
This hash must be updated together with the exact version of Font Awesome, as given on their website.
* Update to FontAwesome 5.5.0
* Add jekyll-include-cache plugin
* Cache "static" includes to improve build performance
* Update CHANGELOG and history
"Static" refers to those includes that don't rely on data passed from the page content.
Deprecate hardcoded footer links in favor or new `footer.links` array for any link and in any order. All of Font Awesome's icons are available for use.
```
footer:
links:
- label: "Twitter"
icon: "fab fa-fw fa-twitter-square"
url: "https://twitter.com/username"
- label: "GitHub"
icon: "fab fa-fw fa-github"
url: "https://github.com/username"
- label: "Instagram"
icon: "fab fa-fw fa-instagram"
url: "https://instagram.com/username"
```
Deprecate social networking links in `_config.yml` in favor or new `author.links` array for any link and in any order. All of Font Awesome's icons are available for use.
```
author:
links:
- label: "Your Website"
icon: "fas fa-fw fa-link"
url: "https://your-site.com"
- label: "Twitter"
icon: "fab fa-fw fa-twitter-square"
url: "https://twitter.com/username"
- label: "GitHub"
icon: "fab fa-fw fa-github"
url: "https://github.com/username"
- label: "Instagram"
icon: "fab fa-fw fa-instagram"
url: "https://instagram.com/username"
```
Fixes#1581
Implement feature #1652 google custom search support. For now we only support the look and feel "results only" and the engine must be set to use that layout. Add a google section to the search providers and search_form and search layout.
Close#1652
Replace sample pages with hard coded HTML and Liquid in favor of a layout that does all the heavy lifting. Assign the appropriate `layout` via YAML Front Matter and away you go.
Where it makes sense replace asset paths and navigation related paths with `relative_url` filter.
Leave SEO related `<head>` elements and social sharing links as `absolute_url`.
Fixes#1588
* Fix canonical URL
* Fix next/previous page paths
* Group meta types together
* Fix twitter:creator conditional
* Allow `author` to accept an object or string
* Reduce white-space
* Add "website" as default `og:type`
* Add `article:modified_time`
* Show `article:modified_time` on `article` only
Fixes#289
