I'd like to use the solved icon as a custom emoji (or just to paste it in a post like this one). The html that discourse uses is the following:
```
<svg class="fa d-icon d-icon-check-square-o svg-icon svg-string"><use xlink:href="#far-check-square"></use></svg>
```

But how can i embed it into a post?

just pasting it won't work: 
before icon <svg class="fa d-icon d-icon-check-square-o svg-icon svg-string"><use xlink:href="#far-check-square"></use></svg> after icon.

Here's the raw variant of this post for quick access: https://meta.discourse.org/raw/101643/102