docs: add beta warnings for the unstable options during livesync

Author: DimitarTachev

lib/services/livesync/livesync-service.ts

@@ -6,6 +6,7 @@ import { hook } from "../../common/helpers";
 import { PACKAGE_JSON_FILE_NAME, LiveSyncTrackActionNames, USER_INTERACTION_NEEDED_EVENT_NAME, DEBUGGER_ATTACHED_EVENT_NAME, DEBUGGER_DETACHED_EVENT_NAME, TrackActionNames } from "../../constants";
 import { DeviceTypes, DeviceDiscoveryEventNames, HmrConstants } from "../../common/constants";
 import { cache } from "../../common/decorators";
+import * as constants from "../../constants";
 
 const deviceDescriptorPrimaryKey = "identifier";
 
@@ -45,6 +46,7 @@ export class LiveSyncService extends EventEmitter implements IDebugLiveSyncServi
 
 	public async liveSync(deviceDescriptors: ILiveSyncDeviceInfo[], liveSyncData: ILiveSyncInfo): Promise<void> {
 		const projectData = this.$projectDataService.getProjectData(liveSyncData.projectDir);
+		this.handleWarnings(liveSyncData, projectData);
 		await this.$pluginsService.ensureAllDependenciesAreInstalled(projectData);
 		await this.liveSyncOperation(deviceDescriptors, liveSyncData, projectData);
 	}
@@ -113,6 +115,18 @@ export class LiveSyncService extends EventEmitter implements IDebugLiveSyncServi
 		return currentDescriptors || [];
 	}
 
+	private handleWarnings(liveSyncData: ILiveSyncInfo, projectData: IProjectData) {
+		if (liveSyncData.useHotModuleReload) {
+			this.$logger.warn("Hot Module Replacement (HMR) is currently in Beta. For more information about the current development state and any known issues, please check the relevant GitHub issue: https://github.com/NativeScript/NativeScript/issues/6398");
+			if (projectData.projectType === constants.NgFlavorName) {
+				this.$logger.warn("To enable Hot Module Replacement (HMR) in Angular projects, follow the steps outlined in this wiki: https://github.com/NativeScript/nativescript-angular/wiki/HMR");
+			}
+		}
+		if (liveSyncData.syncToPreviewApp && liveSyncData.bundle) {
+			this.$logger.warn("Webpack support for the `tns preview` command is currently in Beta. Please, do not hesitate to report any problems that you experience with the feature by opening a new issue in the NativeScript CLI repository: https://github.com/NativeScript/nativescript-cli/issues/new/choose");
+		}
+	}
+
 	private async refreshApplication(projectData: IProjectData, liveSyncResultInfo: ILiveSyncResultInfo, debugOpts?: IDebugOptions, outputPath?: string): Promise<void | IDebugInformation> {
 		const deviceDescriptor = this.getDeviceDescriptor(liveSyncResultInfo.deviceAppData.device.deviceInfo.identifier, projectData.projectDir);