Add default style to icons to automatically adapt their size and position to the surrounding text

[cseguenot]

Hello !

Thank you for this very useful plugin!
To further simplify the integration of icons, since Font Awesome's standard size attributes (ex. fa-sm or fa-x2) are not supported, the following default style should be assigned to all icons:

.size-1 {
  vertical-align: baseline;
  margin: 0 0.3em;
  width: 1em;
  height: 1em;
}

This way, the icons would automatically adapt their size and position to the surrounding text, whether they are placed in a <p> or <h> element for example.