Add alias for `task modify`

I keeo forgetting to say "modify" and even `m` alias did not help.  This
maybe...

dotfiles/bash/main.bashrc

 alias pad4='sed -e "/./s/^/    /"'
 alias grep='grep --color --binary-files=without-match'
 alias sc='se --direction=encz.cz'
+alias taskm='task modify'
 alias ts='ts "%F %T"'
 alias lsblk='lsblk -o +UUID,LABEL'
 alias virsh='virsh --connect qemu:///system'