bashrc fix bash_completion on debian

dotfiles/bash/.bashrc

@@ -19,7 +19,13 @@ fi
 export QT_QPA_PLATFORM=wayland-egl
 export MOZ_ENABLE_WAYLAND=1
 
-source /usr/share/git/git-prompt.sh
+if [ -f '/etc/bash_completion' ]; then
+    # debian
+    source /etc/bash_completion
+else
+    # arch
+    source /usr/share/git/git-prompt.sh
+fi
 PS1='`[ $? = 0 ] || echo "$? "`[\u@\h \w`__git_ps1 " (%s)"`]\$ '
 
 alias ls='ls --color=auto'