debian 11 update source

安装debian 11之后安装软件时发现更新无法找到vim git curl等，需要将/etc/apt/source.list文件进行变更，添加软件源：

deb http://deb.debian.org/debian bullseye main contrib non-free
deb-src http://deb.debian.org/debian bullseye main contrib non-free
deb http://deb.debian.org/debian-security bullseye/updates main contrib non-free
deb-src http://deb.debian.org/debian-security bullseye/updates main contrib non-free
deb http://deb.debian.org/debian bullseye-updates main contrib non-free
deb-src http://deb.debian.org/debian bullseye-updates main contrib non-free

另外，由于我是虚拟机中安装，进行显示器配置时没有1920x1080分辨率设置，执行如下命令设置：

xrandr --newmode "1920x1080"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode Virtual1 1920x1080
xrandr --output Virtual1 --mode 1920x1080