Add Solothurn (#80)

* Add Solothurn

* Update meetups

Co-authored-by: Dennis Reimann <mail@dennisreimann.de>

content/meetups.json

@@ -265,7 +265,7 @@
   },
   {
     "name": "Einundzwanzig Heidelberg",
-    "url": "https://t.me/+kHpDQ9MPBt03NmNi",
+    "url": "https://t.me/Einundzwanzig_HEIDELBERG",
     "top": 60,
     "left": 27,
     "country": "DE",
@@ -439,6 +439,14 @@
     "country": "CH",
     "state": ["Bern"]
   },
+  {
+    "name": "Einezwänzg Solothurn",
+    "url": "https://t.me/+o2gLvxb2SxFhNTI0",
+    "top": 82,
+    "left": 16,
+    "country": "CH",
+    "state": ["Solothurn"]
+  },
   {
     "name": "Bitcoin Zürich",
     "url": "https://www.meetup.com/de-DE/Bitcoin-Meetup-Switzerland/",