feat: make personalInfo customizable

[mintyfrankie]

Refering to #18

Here is a more "flexible" implementation that is not intended to bring breaking change to the template, yet allowing more power-user usage to customize an Info box (for icon, link and text).

A usage of a customizable element in personalInfo is to pass a key-value pair whose key contains custom, and the value being an array with the following keys:

• icon: optional, can pass custom box function to manually insert an icon;
• text: compulsory;
• link: optional, pass a string of hyperlink.

Example:

#import "@preview/fontawesome:0.1.0": *

#let personalInfo = (
  ...
  custom-1: (icon: "", text: "example", link: "https://example.com"),
  ...
)