Disable microsoft telemetry

[Behrooz Amoozad]

I'm not sure if this even fits here, but it would be really nice if the
default bashrc included DOTNET_CLI_TELEMETRY_OPTOUT='true'.
Currently, After installing microsoft .net framework, it has telemetry
enabled by default and it works at least once upon installation. It would
be real nice if it didn't do that, anywhere, at all, not once. And ONLY you
have the power to make this right.
I don't know how many purists are left at gnu, I just hope there are enough
left making decisions for bash.

Thank You.