More API docs

[JunTaoLuo]

Looks like there are more API docs that need to be added for the following:

• Azure
  • Microsoft.AspNetCore.AzureAppServicesIntegration @BrennanConroy
• Caching
  • Microsoft.Extensions.Caching.StackExchangeRedis @JunTaoLuo
  • Microsoft.Extensions.Caching.SqlServer @JunTaoLuo
• DataProtection:
  • Microsoft.AspNetCore.DataProtection @pranavkm
• Features
  • Microsoft.AspNetCore.JsonPatch @SteveSandersonMS
• Http
  • Microsoft.Net.Http.Headers @pranavkm
  • Microsoft.AspNetCore.Http @pranavkm
  • Microsoft.AspNetCore.Http.Extensions @pranavkm
  • Microsoft.AspNetCore.Http.Features @pranavkm
  • Microsoft.AspNetCore.Owin @JamesNK
  • Microsoft.AspNetCore.WebUtilities @pranavkm
• JSInterop
  • Microsoft.JSInterop @pranavkm
• ObjectPool
  • Microsoft.Extensions.ObjectPool @pranavkm
• Razor
  • Microsoft.AspNetCore.Razor @TanayParikh
• Security
  • Microsoft.AspNetCore.Authentication.Twitter @HaoK
• Server
  • Microsoft.AspNetCore.Connections.Abstractions @halter73
  • Microsoft.AspNetCore.Server.Kestrel.Core @sebastienros
  • Microsoft.AspNetCore.Server.Kestrel.Transport.Experimental.Quic @sebastienros
  • Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets @sebastienros
• SignalR
  • Microsoft.AspNetCore.SignalR.Specification.Tests @BrennanConroy
• WebEncoders
  • Microsoft.Extensions.WebEncoders @JunTaoLuo

[JunTaoLuo]

We'll need to divide this up fyi @pranavkm

[dougbu]

@JunTaoLuo please check if #27285 already lists the problem areas you mentioned above. If not, please mention this issue in the description.