Fix some typos, improve some descriptions

_data/help.json

@@ -1,7 +1,7 @@
 [{
 	"title": "Forum",
 	"icon": "question-circle",
-	"description": "A big german community with a section about Vocaluxe. The devs are acitve there and could help with (nearly) every problem.",
+	"description": "A big german community with a section dedicated to Vocaluxe. The developers are active there and happy to help with any problems related to the game.",
 	"url_text": "Ask your questions!",
 	"url": "http://forum.ultra-star.de"
 },
@@ -9,13 +9,13 @@
 	"title": "Wiki",
 	"icon": "book",
 	"description": "You can find some nice and helpful articles in our GitHub-wiki. Feel free to improve it, if something is missing.",
-	"url_text": "Start some reading...",
+	"url_text": "Start reading...",
 	"url": "https://github.com/Vocaluxe/Vocaluxe/wiki"
 },
 {
 	"title": "Facebook",
 	"icon": "facebook-square",
-	"description": "Follow us on facebook to get all news about Vocaluxe - And if there are questions, just ask!",
+	"description": "Follow us on Facebook to get all news about Vocaluxe - And if there are questions, just ask!",
 	"url_text": "Give us a like!",
 	"url": "https://www.facebook.com/Vocaluxe"
 }]