feat(theme,interfaces): Introduce a global theming system and unify menu/tab interfaces; migrate components to use themeDefaultStyles and update APIs accordingly

ts_web/elements/00group-editor/dees-editor-markdown/dees-editor-markdown.ts

@@ -8,6 +8,7 @@ import {
   cssManager,
   domtools
 } from '@design.estate/dees-element';
+import { themeDefaultStyles } from '../../00theme.js';
 
 const deferred = domtools.plugins.smartpromise.defer();
 
@@ -22,8 +23,10 @@ export class DeesEditorMarkdown extends DeesElement {
   public static demo = () => html`<dees-editormarkdown></dees-editormarkdown>`;
 
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       .gridcontainer {
         position: absolute;
         height: 100%;