Add links to @dotnet/ teams in area-owners.md

[krwq]

I noticed that the area-owners.md file does not have links to the @dotnet teams and it's a bit inconvenient to check who actually owns it.

This was created with:
Find: @dotnet/(\S+)
Replace: [@dotnet/$1](https://github.com/orgs/dotnet/teams/$1)

and reformat markdown table in sublime text

I validated couple of random links for correctness but did not click all of them.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-meta
See info in area-owners.md if you want to be subscribed.

[huoyaoyuan]

The teams link may not be visible to users out of the organization, and can cause confusion.

[krwq]

I didn't realize that - I find it very often I need to talk to the owners but seeing that owner of area-XYZ is @dotnet/area-XYZ seems a bit annoying - perhaps as alternative we could mention owners directly (but that will be a tiny bit more work than just regex and harder to keep up to date).

As the counter argument even bot's post above is linking the area and haven't heard about anyone complaining that it's confusing. [EDIT] and now that I opened this PR in private browser window it seems it's linked only when I'm logged in so maybe bad argument. Perhaps we could request this feature from github instead