Add dotnet

[Miniontoby]

Hi,

is this repo still 'active'?

I would like dotnet images. I can help, since I am already working on them.

Base image would be mcr.microsoft.com/dotnet/runtime:<VERSION>-alpine

At least versions 6, 7 and 8 would be logical to add, since 6 is the last LTS version and 8 is the newest (and LTS).

• mcr.microsoft.com/dotnet/runtime:6.0-alpine
• mcr.microsoft.com/dotnet/runtime:7.0-alpine
• mcr.microsoft.com/dotnet/runtime:8.0-alpine

But yeah, if I were to make it and make a PR, will it be merged?