Merge pull request plone#1264 from plone/add-volto-slate-glossary

Add glossary terms: slate, volto-slate and elementEditor

Author: stevepiercy

docs/glossary.md

@@ -319,7 +319,19 @@ Classic UI
     Its theme is named [Barceloneta](https://github.com/plone/plonetheme.barceloneta/).
     It is based on Twitter Bootstrap 5.
     It uses [Mockup](https://github.com/plone/mockup/) as its JavaScript stack.
-    [View Mockup's patterns](https://plone.github.io/mockup/dev/). 
+    [View Mockup's patterns](https://plone.github.io/mockup/dev/).
 
     The other frontend is {term}`Volto`.
+
+Slate
+    [Slate.js](https://docs.slatejs.org/) is a highly customizable platform for creating rich-text editors, also known as `WYSIWYG` editors.
+    It enables you to create powerful, intuitive editors similar to those you've probably used in Medium, Dropbox Paper, or Google Docs.
+
+volto-slate
+    `volto-slate` is an interactive default text editor for Volto, developed on top of {term}`Slate` while offering enhanced WYSIWYG functionality and behavior.
+
+elementEditor
+    A generic {term}`volto-slate` plugin architecture that can be used to create other editor interactions that follow the pattern of having a button that toggles a format (an inline element).
+    It also creates a separate edit form for advanced customization of the data attached to the element.
+
 ```