Add Jekyll SEO plugin

[jbampton]

• Add all the Apple touch and Microsoft icons
• Fix Jekyll config error
• Add a browserconfig.xml file
• Add alt, title, width and height attributes to images
• Add lang="en" to the start html tag
• Add meta viewport tag
• Created maskable icon
• Created Safari pinned tab icon
• Add all the Android icon sizes
• Set favicon.ico to 48px square
• Strip blank line from HTML
• Fix missing HTTPS on link
• refs Fix Google Lighthouse errors #85
• refs Favicon errors and tester #89

https://webhint.io/docs/user-guide/hints/hint-apple-touch-icons/
https://github.com/jekyll/jekyll-seo-tag

When running bundle exec jekyll serve

In Safari desktop browser they have the concept of a pinned tab and you can have a different icon for a pinned tab.
Depending on what color the tab bar is it should look like this:

[jbampton]

https://web.dev/add-manifest/
https://developer.mozilla.org/en-US/docs/Web/Manifest/icons
https://stackoverflow.com/questions/23043429/what-is-a-simple-minimal-browserconfig-xml-for-a-web-site

In the manifest we now have all the icons with the maskable icon seen at the bottom of the manifest.
This is how it looks in Firefox:

[jbampton]

refs #85

You may not get the same scores on each Lighthouse run.

Before from the PDF:

Now on my local machine:

[jbampton]

The SEO score should go higher when it's tested on the real domain.

[jbampton]

Jekyll SEO adds some HTML markup to the HTML head tag.

It uses the Open Graph Protocol and JSON for Linking Data

The Open Graph protocol enables any web page to become a rich object in a social graph. For instance, this is used on Facebook to allow any web page to have the same functionality as any other object on Facebook.

Data is messy and disconnected. JSON-LD organizes and connects it, creating a better Web.

https://ogp.me/
https://json-ld.org/
https://search.google.com/structured-data/testing-tool
https://developers.facebook.com/tools/debug/

[jbampton]

You can also test a website here -> https://web.dev/measure/

Similar scores and some of the same tests.

[jbampton]

Hey @matz this one is ready for review 👍 🚀 💯