[FEATURE]: refer to your own icon

[tushev]

What would you like to be added/improved?

Many of us have custom skills that are not present in common icon providers. It would be nice to have them in UI as well instead of adding them later within code.

Describe the solution you'd like

An 'extra skill' form that asks for name/id, alt text, and icon URL, and then adds it to the tech list. The image must be already hosted by a user somewhere (ideally, in his README repo on github).

Additional context

Maybe the 'tech' should be reusable among session, so if a user accidentally deletes it from his tech lists, it remains as an option in available icons, until the page is reloaded/localStorage cleared.