Windows HostProcess Container Documentation (#28413)

* Rebasing HostProcess security changes.

* Incorporated initial round of feedback

* Minor wording updates

* Finished up remaining todo items

* Apply suggestions from code review

Co-authored-by: Jordan Liggitt <jordan@liggitt.net>
Co-authored-by: Mark Rossetti <marosset@microsoft.com>

* Moved HostProcess security documentation into PSS and create-host-process-pod docs

* Updated with for James' review

* Apply suggestions from code review

Co-authored-by: Tim Bannister <tim@scalefactory.com>
Co-authored-by: James Sturtevant <jsturtevant@gmail.com>

* Minor edits

* Modifications for additional feedback

Co-authored-by: Jordan Liggitt <jordan@liggitt.net>
Co-authored-by: Mark Rossetti <marosset@microsoft.com>
Co-authored-by: Tim Bannister <tim@scalefactory.com>
Co-authored-by: James Sturtevant <jsturtevant@gmail.com>

content/en/docs/reference/command-line-tools-reference/feature-gates.md

@@ -460,6 +460,7 @@ different Kubernetes components.
 | `WindowsGMSA` | `false` | Alpha | 1.14 | 1.15 |
 | `WindowsGMSA` | `true` | Beta | 1.16 | 1.17 |
 | `WindowsGMSA` | `true` | GA | 1.18 | - |
+| `WindowsHostProcessContainers` | `false` | Alpha | 1.22 |
 | `WindowsRunAsUserName` | `false` | Alpha | 1.16 | 1.16 |
 | `WindowsRunAsUserName` | `true` | Beta | 1.17 | 1.17 |
 | `WindowsRunAsUserName` | `true` | GA | 1.18 | - |
@@ -987,6 +988,7 @@ Each feature gate is designed for enabling/disabling a specific feature:
 - `WinDSR`: Allows kube-proxy to create DSR loadbalancers for Windows.
 - `WinOverlay`: Allows kube-proxy to run in overlay mode for Windows.
 - `WindowsGMSA`: Enables passing of GMSA credential specs from pods to container runtimes.
+- `WindowsHostProcessContainers`: Enables support for Windows HostProcess containers.
 - `WindowsRunAsUserName` : Enable support for running applications in Windows containers
   with as a non-default user. See
   [Configuring RunAsUserName](/docs/tasks/configure-pod-container/configure-runasusername)