Preload fonts

[mestradanu]

The theme needs the fonts to be preloaded for best practices and optimization.

Notes:

• If the font is loaded with a parameter (e.g. ?qop3op) like icon fonts sometimes do, the preload tag must also have that parameter.
• Reference the main theme in NU for how to implement this.
• Test with the "Lighthouse" tab in Google Chrome, specifically the "Preload key requests" section in the "Performance" test.

[mestradanu]

Hey @agameronu we need to switch out the call get_stylesheet_directory_uri() to get_template_directory_uri() since this theme is used as a parent theme. the stylesheet function will point to the current (child) theme and not the theme it belongs to (parent/template).