Implement notifications + "mute/unmute chat" menu

    - Added icons: Pinned and muted chats have icons. It's from Twemoji font, I've added
    credits in the README.md and source code of ChatlistItem.qml. I prefer to rely on .PNG for this
    one because icon might not be installed or exist on the system, and we avoid
    the black box problem.
    - Modified CMakeLists: added KNotifications as a required library
    - Modified build.sh: I cannot comprehend how the install(FILES)
    function from cmake works, so I used good old install from GNU coreutils.
    It copies usr/ structure and needed files (.desktop and .notifyrc) for
    KNotifications to work.
    - Aesthetic changes: context menu is shorter now due to the text
    being state-aware. You can now also mute a chat so you won't be notified
    on incoming messages.

1 files changed, 4 insertions, 0 deletions

diff --git a/README.md b/README.md
index 1922507..506b251 100644..100755
--- a/README.md
+++ b/README.md
@@ -156,6 +156,10 @@ icon theme for Qt 5 there and set `QT_QPA_PLATFORMTHEME=qt5ct` or
 Setting `XDG_CURRENT_DESKTOP=GNOME` environment variable has also been reported
 to help in this case. This results in usage of Adwaita icon theme.
 
+# Credits
+
+The pinned and muted chat icons are converted to PNG from the [Twemoji](https://twemoji.twitter.com/) font. Licensed under [CC-BY 4.0](https://creativecommons.org/licenses/by/4.0/) - Copyright 2020 Twitter, Inc and other contributors.
+
 # License
 
 This program is free software: you can redistribute it and/or modify