Improve i3 configurations to work alongside Plasma

+ Add alias to restart plasmashell
+ Fix date display in conky for i3 sessions
+ Fix polybar height for better display with new font size
+ Add floating rules in i3 for Steam and Signal
+ Use i3 configuration to bind custom keys instead of xbindkeys
+ Relocate `.desktop` files to `.local/share/applications`
+ Symlink desktop files for startup applications to `.config/autostart`

.config/autostart/mullvad-vpn.desktop

@@ -1,21 +0,0 @@
-[Desktop Entry]
-Categories=Network;
-Comment[en_US]=Mullvad VPN client
-Comment=Mullvad VPN client
-Exec="/opt/Mullvad VPN/mullvad-vpn" %U
-GenericName[en_US]=
-GenericName=
-Icon=mullvad-vpn
-MimeType=
-Name[en_US]=Mullvad VPN
-Name=Mullvad VPN
-Path=
-StartupNotify=true
-StartupWMClass=Mullvad VPN
-Terminal=false
-TerminalOptions=
-Type=Application
-X-DBUS-ServiceName=
-X-DBUS-StartupType=
-X-KDE-SubstituteUID=false
-X-KDE-Username=

.config/autostart/mullvad-vpn.desktop

@@ -0,0 +1 @@
+.local/share/applications/mullvad-vpn.desktop