chore: Add docs for virus scanner exclusions (#1378)

docs/FAQ.md

@@ -25,6 +25,9 @@ Standards have been documented on [Unit Test Bar and Standards](UnitTestBarAndSt
 #### Q. What about UI tests?
 Refer to the [UI Tests](../src/UITests/README.md) readme.
 
+#### Q. Why do I sometimes see delays when starting the app or running UI tests?
+This may be a result of your local virus scanner. [Virus Scanner Exclusions](VirusScannerExclusions.md) provides more information.
+
 #### Q. How do I go about making internal interfaces available for testing? 
 Please visit [Accessing Internals](AccessingInternals.md).
 

docs/VirusScannerExclusions.md

@@ -0,0 +1,23 @@
+<!--
+Copyright (c) Microsoft Corporation. All rights reserved.
+Licensed under the MIT License.
+-->
+
+## Virus scanner exclusions
+
+When running locally, virus scanners have been known to have a significant impact on execution time. To prevent this, you may wish to exclude the entire repo from virus scanning. The specifics of how to do this will vary between virus scanners, between operating systems, and possibly between different versions of the same virus scanner.
+
+### Microsoft Defender (Windows only)
+The following steps allow you to exclude a folder and all its descendants from Microsoft Defender. These instructions have been validated on both Windows 10 and Windows 11:
+- From the start menu, run **Windows Security**
+- Enter the **Virus & threat protection** tab
+- Under **Virus & threat protection settings**, click **Manage settings**
+- Under **Exclusions**, click **Add or remove exclusions**
+- If prompted for permissions, grant permissions
+- Click **Add an exclusion**
+- Select **Folder** as the exclusion type
+- Specify the folder to ignore--all descendants of this folder will be ignored
+- Click **Select folder**
+
+### Other antivirus products
+Please consult your antivirus product's documentation.