Please add option to disable all css props except font-family/content
Would be nice to do something like this:
```
.jm-icon {
  $icons: (
    'email',
    'star',
    'star-filled',
    'chevron-left'
  );

  text-rendering: auto;
  -webkit-font-smoothing: auto;
  -moz-osx-font-smoothing: auto;
  font-weight: normal;
  line-height: 1;
  
  &:before {
    display: block;
  }

  @each $icon in $icons {
    &--#{$icon}:before {
      font-icon: url('../static/images/v2/single-color/#{$icon}.svg');
    }
  }
}
```

So `:before {}` blocks would have only following code
```
.jm-icon--star:before {
  font-family: z90da5;
  font-weight: normal;
}
```