💬(frontend) rephrase entry text as question for politeness

Change entry text to interrogative form to make it sound more polite and
welcoming. Improves tone and friendliness of the user interface through
more considerate language.

src/frontend/src/locales/en/rooms.json

@@ -23,7 +23,7 @@
       "title": "Effects",
       "subTitle": "Configure your camera's effects."
     },
-    "heading": "Join the meeting",
+    "heading": "Join the meeting?",
     "joinLabel": "Join",
     "joinMeeting": "Join meeting",
     "toggleOff": "Click to turn off",

src/frontend/src/locales/fr/rooms.json

@@ -18,7 +18,7 @@
       "enable": "Activer le micro",
       "label": "Microphone"
     },
-    "heading": "Rejoindre la réunion",
+    "heading": "Rejoindre la réunion ?",
     "effects": {
       "description": "Appliquer des effets",
       "title": "Effets",