Add documentation for VFS introduced in dotnet/efcore#34864. (#43833)

Author: cincuranet

docs/standard/data/sqlite/connection-strings.md

@@ -106,6 +106,13 @@ A value indicating whether the connection will be pooled.
 | True  | The connection will be pooled. This is the default. |
 | False | The connection won't be pooled.                     |
 
+### Vfs
+
+A value indicating which [virtual file system (VFS)](https://www.sqlite.org/vfs.html) implementation to use. When empty or not specified, the default VFS for the platform is used.
+
+> [!NOTE]
+> The Vfs keyword was added in version 10.0.
+
 ## Connection string builder
 
 You can use <xref:Microsoft.Data.Sqlite.SqliteConnectionStringBuilder> as a strongly typed way of creating connection strings. It can also be used to prevent connection string injection attacks.