i18n: the chromes are named Classic and Modern (beta)

The ribbon is the look users know as classic, the floating island the modern
one; beta because it has no entry point yet for comments, revisions, line
numbering or page design. Mode ids keep naming the shape.

src/lib/i18n/locales/de.ts

@@ -846,12 +846,14 @@ const de: Messages = {
     cellMargins: 'Zellenränder',
     altText: 'Alternativtext',
     altTextHint: 'Das Bild beschreiben',
+    // Keyed by the mode id, which names the shape: the ribbon is the look users
+    // know as classic, the floating island the modern one.
     chrome: {
       title: 'Symbolleisten-Stil',
-      ribbon: 'Menüband',
+      ribbon: 'Klassisch',
       ribbonHint: 'Mit Registerkarten, wie in Word',
-      classic: 'Klassisch',
-      classicHint: 'Die schwebende Symbolleiste',
+      classic: 'Modern (beta)',
+      classicHint: 'Eine schwebende Symbolleiste',
     },
   },
   app: {

src/lib/i18n/locales/en.ts

@@ -850,12 +850,14 @@ const en = {
     cellMargins: 'Cell margins',
     altText: 'Alt text',
     altTextHint: 'Describe the image',
+    // Keyed by the mode id, which names the shape: the ribbon is the look users
+    // know as classic, the floating island the modern one.
     chrome: {
       title: 'Toolbar style',
-      ribbon: 'Ribbon',
+      ribbon: 'Classic',
       ribbonHint: 'Tabbed, like Word',
-      classic: 'Classic',
-      classicHint: 'The floating toolbar',
+      classic: 'Modern (beta)',
+      classicHint: 'One floating toolbar',
     },
   },
   app: {