add links of usable items

docs/eln/admin/text_templates.mdx

@@ -19,7 +19,7 @@ open an editor that lets you configure custom `text templates`:
 ![text_template_editor](/img/admin_ui/text_template_editor.png)
 
 Click on the <Btn mixed={[faPlus]} color={"primary"}/> button to generate a new `text template`.
-You can then configure an icon (TODO: which icons can be used?), a `Text` (TODO: what's that for?), as well as a the paragraph that's meant to appear as a template in the users' text editors.
+You can then configure an icon ([Font Awesome](https://fontawesome.com/),[Bootstrap glyphicons](https://getbootstrap.com/docs/3.3/components/) or internal chemotion eln icons), a `Text` (TODO: what's that for?), as well as a the paragraph that's meant to appear as a template in the users' text editors.
 
 ![text_template_edited](/img/admin_ui/text_template_edited.png)