🎁 Add onDidChangeShell event to ext host

Signed-off-by: Babak K. Shandiz <babak.k.shandiz@gmail.com>

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -309,6 +309,9 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			get shell() {
 				return extHostTerminalService.getDefaultShell(false);
 			},
+			get onDidChangeShell() {
+				return extHostTerminalService.onDidChangeShell;
+			},
 			get isTelemetryEnabled() {
 				return extHostTelemetry.getTelemetryConfiguration();
 			},