tweak: label session view as beta

I want to do more to it, but that might have to wait for a bit.

Author: ProbablePrime

views/index.pug

@@ -7,7 +7,7 @@ block content
     p Would you like to
     ul
         li
-            a(href="/sessions") See the current active public sessions
+            a(href="/sessions") See the current active public sessions (BETA)
         li
             a(href="https://resonite.com") Go to our Main Website?