Improve About page icons handling

[arkid15r]

Is your feature request related to a problem? Please describe.
Currently devicons require an external .css file
Due to this we have to whitelist cdn.jsdelivr.net in proxy/security.conf

Describe the solution you'd like
Replace icons with inline SVGs and clean up index.html and security.conf after that.

Are you going to work on implementing this?

• Yes
• No

[M-ayank2005]

@arkid15r I would like to work on this issue. Please assign it to me. Thanks