feat: add iconClass prop

[ajmueller]

I use Tailwind CSS and would like to be able to add classes to the svg element, thereby allowing me to use stroke and fill classes with any custom theming I've applied and not rely on resolving my Tailwind config or Tailwind's colors exported in their package.

In addition, I fixed a few security vulnerabilities (noticed them when I installed the deps) as well as added some VS Code settings and extension recommendations due to conflicts with my own setup that uses Prettier as the default formatter.

Let me know what you think and if there's anything else you'd like me to change (e.g. bump the version).