add Key for muting Mic
add Key for muting Mic

 * this exists on most IBM/Lenovo Thinkpads

dump of `xev`:

KeyPress event, serial 34, synthetic NO, window 0x2e00001,
    root 0x97, subw 0x0, time 306796922, (668,272), root:(670,293),
    state 0x0, keycode 198 (keysym 0x1008ffb2, XF86AudioMicMute), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False
KeyRelease event, serial 34, synthetic NO, window 0x2e00001,
    root 0x97, subw 0x0, time 306796922, (668,272), root:(670,293),
    state 0x0, keycode 198 (keysym 0x1008ffb2, XF86AudioMicMute), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

nxnfufunezn/qtile,nxnfufunezn/qtile,himaaaatti/qtile,zordsdavini/qtile,andrewyoung1991/qtile,w1ndy/qtile,ramnes/qtile,andrewyoung1991/qtile,frostidaho/qtile,rxcomm/qtile,kiniou/qtile,de-vri-es/qtile,rxcomm/qtile,xplv/qtile,apinsard/qtile,qtile/qtile,encukou/qtile,EndPointCorp/qtile,farebord/qtile,flacjacket/qtile,kiniou/qtile,jdowner/qtile,soulchainer/qtile,zordsdavini/qtile,de-vri-es/qtile,kseistrup/qtile,flacjacket/qtile,farebord/qtile,dequis/qtile,jdowner/qtile,aniruddhkanojia/qtile,EndPointCorp/qtile,cortesi/qtile,qtile/qtile,StephenBarnes/qtile,w1ndy/qtile,dequis/qtile,xplv/qtile,kseistrup/qtile,himaaaatti/qtile,kynikos/qtile,encukou/qtile,cortesi/qtile,ramnes/qtile,tych0/qtile,apinsard/qtile,frostidaho/qtile,kynikos/qtile,tych0/qtile,kopchik/qtile,kopchik/qtile,StephenBarnes/qtile,aniruddhkanojia/qtile,soulchainer/qtile