Social Icon Additions

Answering my own question, it is relatively easy to add more Font awesome icons.

I aded this to the custom css:

.social-navigation a[href*="t.me"] {
  font-size: 0;
}
.social-navigation a[href*="t.me"]:before {
  content: "\f2c6";
}

.social-navigation a[href*="gitlab.com"] {
  font-size: 0;
}
.social-navigation a[href*="gitlab.com"]:before {
  content: "\f296";
}