[refactor] Relocate links placed in header

[Hamdrive]

Noticed that all the Google fonts, Font Awesome icons were being repetitively imported into each HTML file, which seems redundant.
It would be a better approach if it was directly imported into a main CSS file which can be easily referred to by all other files.

Additionally, consider using the FontAwesome CDN link instead of the current script

Chore:

1. Move link imports to CSS, cleanup all HTML
2. Remove FontAwesome script in header, instead use CDN link