Adding an area-ownership document (#20108)

Author: mkArtakMSFT

docs/area-owners.md

@@ -0,0 +1,23 @@
+The below table lists all the `area-`labels used in the `aspnetcore` repository and their owners:
+
+| Area label | Owner | Description|
+|--- | ---| --- |
+| area-azure | anurse | |
+| area-blazor | mkArtakMSFT | Blazor server and Blazor WASM related |
+| area-commandlinetools | anurse, mkArtakMSFT | dev certs, dotnet watch,  |
+| area-dataprotection | anurse | |
+| area-grpc | shirhatti | |
+| area-healthchecks | rynowak | |
+| area-hosting | anurse | |
+| area-httpclientfactory | anurse | |
+| area-identity | blowdart | |
+| area-infrastructure | dougbu | |
+| area-installers | anurse | |
+| area-middleware | anurse | |
+| area-mvc | mkArtakMSFT | |
+| area-perf | anurse | |
+| area-platform | anurse | |
+| area-security | blowdart | |
+| area-servers | anurse | |
+| area-signalr | anurse | |
+| area-websockets | anurse | |