MDL-80058 editor_tiny: add preformatted format to the blocks

lib/editor/tiny/amd/src/editor.js

@@ -268,7 +268,7 @@ const getStandardConfig = (target, tinyMCE, options, plugins) => {
         // Override the standard block formats property (removing h1 & h2).
         // https://www.tiny.cloud/docs/tinymce/6/user-formatting-options/#block_formats
         // eslint-disable-next-line camelcase
-        block_formats: 'Paragraph=p; Heading 3=h3; Heading 4=h4; Heading 5=h5; Heading 6=h6;',
+        block_formats: 'Paragraph=p; Heading 3=h3; Heading 4=h4; Heading 5=h5; Heading 6=h6; Preformatted=pre',
 
         // The list of plugins to include in the instance.
         // https://www.tiny.cloud/docs/tinymce/6/editor-important-options/#plugins