i18n: the phonetic guide is called ruby text

Word and LibreOffice hide theirs unless an East Asian language is on; ours is
always in the Insert tab, so the label says what it inserts. The reading field
no longer repeats the dialog's own name.

src/lib/i18n/locales/de.ts

@@ -42,9 +42,9 @@ const de: Messages = {
     },
   },
   ruby: {
-    title: 'Phonetische Zeichen',
+    title: 'Ruby-Text',
     base: 'Basistext',
-    reading: 'Ruby-Text',
+    reading: 'Lesung',
   },
   autoText: {
     title: 'AutoText',

src/lib/i18n/locales/en.ts

@@ -42,10 +42,12 @@ const en = {
       urls: '',
     },
   },
+  // Word and LibreOffice call this the (Asian) phonetic guide and hide it unless an
+  // East Asian language is on. Ours is always there, so it says what it inserts.
   ruby: {
-    title: 'Phonetic guide',
+    title: 'Ruby text',
     base: 'Base text',
-    reading: 'Ruby text',
+    reading: 'Reading',
   },
   autoText: {
     title: 'AutoText',