[Announce] updated Linux install script

To go along with the v2 beta I have updated the Linux install script to have some more command line switches to hopefully give you more control of what you may want to install

as usual you can run it from remote

bash <(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-nodered)

but you can add parameters eg --help to the end of the command to see more options
So for example to force install nodejs 14 and try the new beta and then restart you could

bash <(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-nodered) --node14 --nodered-version="next" --restart

As usual - comments and issues here please.