Real time communication improvements (#1147)

* voice-video-messenger: remove duplicates with instant-messenger

also move Tox and Jami to Instant Messengers, Change Jitsi to Jitsi Meet

* instant-messenger: remove platforms of Signal Desktop

https://github.com/privacytoolsIO/privacytools.io/issues/967#issuecomment-520268788

* instant-messenger: add indepedent security audits

* voice-video-messenger: mention that many are already listed above

* instant-messenger: fix formatting & mention features of Jami

* voice-video-messenger: list Mumble

* update source_code.md

* voice-video-messenger: fix card

* add Mumble.png

* Small revisions to the instant messengers

* Spelling!

* voice-video-messenger: add a warning on Jitsi Meet WebRTC

* instant-messenger: remove a from Jami

* instant-messenger: add VoIP badges

* Use updated label functionality

The labels/badges functionality added to cardv2.html in cbe5de4cc2 work better here.

* Fix Jitsi Meet warning badge

source_code.md

@@ -134,26 +134,24 @@ Backend: closed-source
 
  Status.im: https://github.com/status-im
 
+ Tox: https://github.com/TokTok/c-toxcore
+
+ Ring/Jami: https://git.jami.net/savoirfairelinux
+
 ## Team chat
 
  Rocket.chat: https://github.com/rocketchat/
  
  Keybase: https://github.com/Keybase
 
-## Encrypted Video & Voice Messenger
- Signal: https://github.com/signalapp
-
- Wire: https://github.com/wireapp
-
+## Video & Voice Messenger
  Linphone: https://github.com/BelledonneCommunications/
 
+ Mumble: https://github.com/mumble-voip/
+
    Worth Mentioning
 
- Jitsi: https://github.com/jitsi/jitsi-meet
-
- Tox: https://github.com/TokTok/c-toxcore
-
- Ring/Jami: https://gerrit-ring.savoirfairelinux.com/#/q/status:open
+ Jitsi Meet: https://github.com/jitsi/jitsi-meet
 
  ## File Sharing
   OnionShare: https://github.com/micahflee/onionshare