Add new media type name

[MichielDG]

I have added image/png because it is a common media type and don't know why it's not in there.

[Dotnet-GitSync-Bot]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, to please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[ghost]

Tagging @dotnet/ncl as an area owner

[dnfclas]

All CLA requirements met.

[ManickaP]

@MichielDG is this PR based on any issue? If yes, could you link it please?

If not, then since this is a public type, we need to go through api review process. We should start with filing an issue tagged as an api-suggestion, then we can move on from that.

Could you file such an issue? For example look into this one, that's one I filed recently. If you need help, feel free to ping me, I'll gladly guide you through the process.

[MichielDG]

@ManickaP I've created an issue for this: #34758

[ManickaP]

Thanks, I'll bring it up in today's meeting so it can move forward.

[stephentoub]

Thanks for the PR, @MichielDG. We generally welcome unsolicited PRs, but for new APIs in particular, we're more stringent and have a process we follow, outlined at https://github.com/dotnet/runtime/blob/master/docs/project/api-review-process.md; it requires approved APIs before PRs to implement them. There's an issue at #1489 tracking adding additional media types, and it's waiting for someone to propose the concrete set of additions; we'd welcome your help in fleshing that out with a concrete proposal. In the meantime, I'm going to close this. Thanks, again.