Refactor preview flag to be more clear (#134)

***NO_CI***

Author: networkfusion

README.md

@@ -184,12 +184,12 @@ nanoff --target ST_STM32F769I_DISCOVERY --deploy --image "E:\GitHub\nf-Samples\s
 
 ### Update the firmware of a ST_STM32F769I_DISCOVERY along with a managed application
 
-To update the firmware of the ST_STM32F769I_DISCOVERY target to the latest available preview version, using a JTAG connection, along with a managed application.
+To update the firmware of the ST_STM32F769I_DISCOVERY target to the latest available version, using a JTAG connection, along with a managed application.
 You have to specify the path to the managed application.
 This example uses the binary format file that is generated by Visual Studio when building any nanoFramework C# application. Because it's a binary file you have to specify too the flash address of the deployment region (here 0x08000000, mind the hexadecimal format).
 
 ```console
-nanoff --update --target ST_STM32F769I_DISCOVERY --preview --jtag --binfile "c:\dev\my awesome app\bin\debug\my_awesome_app.bin" --address 0x08000000
+nanoff --update --target ST_STM32F769I_DISCOVERY --jtag --binfile "c:\dev\my awesome app\bin\debug\my_awesome_app.bin" --address 0x08000000
 ```
 
 ### List all STM32 devices available with JTAG connection
@@ -297,21 +297,21 @@ Available COM ports:
 
 ## List targets
 
-You can list the supported targets, their versions, either for stable versions or preview. `--platform` allows you to filter for a platform. `--preview` filters the query to show only preview versions.
+You can list the supported targets, and their version using the `--platform` parameter.
 
-List packages available for ESP32 targets in preview version.
+List packages available for ESP32 targets:
 
 ```console
-nanoff --listboards --platform esp32 --preview
+nanoff --listboards --platform esp32
 ```
 
-List packages available for STM32 targets in (stable version).
+List packages available for STM32 targets:
 
 ```console
 nanoff --listboards --platform stm32
 ```
 
-If you just use `--listtargets` switch, you'll get the list of all the stable packages for all targets.
+If you use the `--listtargets` switch in conjunction with `--preview`, you'll get the list of packages that maybe used for experimental or major feature changes.
 
 ## Clear cache location
 

README.zh-cn.md

@@ -184,7 +184,7 @@ nanoff --target ST_STM32F769I_DISCOVERY --deploy --image "E:\GitHub\nf-Samples\s
 本例使用了Visual Studio在构建任何nanoFramework c#应用程序时生成的二进制格式文件。 因为它是一个二进制文件，所以您还必须指定部署区域的flash地址(这里是0x08000000，注意十六进制格式)。  
 
 ```控制台
-nanoff --update --target ST_STM32F769I_DISCOVERY --preview --jtag --binfile "c:\dev\my awesome app\bin\debug\my_awesome_app.bin" --address 0x08000000
+nanoff --update --target ST_STM32F769I_DISCOVERY --jtag --binfile "c:\dev\my awesome app\bin\debug\my_awesome_app.bin" --address 0x08000000
 ```
 
 ### 列出JTAG连接中可用的所有STM32设备  
@@ -264,12 +264,12 @@ nanoff -v q
 ## 目标列表
 
 翻译结果
-您可以列出支持的目标及其版本，用于稳定版本或预览。 `--platform` 允许您过滤平台。 `--preview` 过滤查询以仅显示预览版本。 
+您可以列出支持的目标及其版本，用于稳定版本或预览。 `--platform` 允许您过滤平台。 
 
 在预览版本中列出可用于ESP32目标的软件包。  
 
 ```控制台
-nanoff --listboards --platform esp32 --preview
+nanoff --listboards --platform esp32
 ```
 
 列出可用于STM32目标的包(稳定版本)。  

nanoFirmwareFlasher/Options.cs

@@ -234,7 +234,7 @@ public class Options
             "preview",
             Required = false,
             Default = false,
-            HelpText = "Preview version. Will download the firmware package from the preview repository.")]
+            HelpText = "Download a firmware package from the preview repository that includes major changes or experimental features.")]
         public bool Preview { get; set; }
 
         [Option(
@@ -306,14 +306,13 @@ public class Options
         public static IEnumerable<Example> Examples =>
             new List<Example>
             {
-                new("- Update ESP32 WROVER Kit device with latest available firmware (stable version)", new Options { TargetName = "ESP_WROVER_KIT", Update = true }),
-                new("- Update specific STM32 device (ST_STM32F769I_DISCOVERY) with latest available firmware (preview version), using JTAG interface", new Options { TargetName = "ST_STM32F769I_DISCOVERY" , Update = true, Preview = true, JtagUpdate = true}),
+                new("- Update ESP32 WROVER Kit device with latest available firmware", new Options { TargetName = "ESP_WROVER_KIT", Update = true }),
+                new("- Update specific STM32 device (ST_STM32F769I_DISCOVERY) with latest available firmware, using JTAG interface", new Options { TargetName = "ST_STM32F769I_DISCOVERY" , Update = true, JtagUpdate = true}),
                 new("- Update ESP32 device with latest available firmware (stable version), device is connected to COM31", new Options { TargetName = "ESP32_PSRAM_REV0", Update = true, SerialPort = "COM31" }),
                 new("- Update ESP32 device with custom firmware (local bin file)", new Options { TargetName = "ESP_WROVER_KIT" , DeploymentImage = "<location of file>.bin"}),
-                new("- Update specific STM32 device (NETDUINO3_WIFI) with latest available firmware (preview version), device is connected through DFU with Id 3380386D3134", new Options { TargetName = "NETDUINO3_WIFI",  Update = true, Preview = true, DfuDeviceId = "3380386D3134" }),
                 new("- List all STM32 devices connected through JTAG", new Options { Platform = SupportedPlatform.esp32, ListJtagDevices = true}),
                 new("- Install STM32 JTAG drivers", new Options { InstallJtagDrivers = true}),
-                new("- List all available STM32 targets", new Options { ListTargets = true, Preview = true, Platform =  SupportedPlatform.stm32 }),
+                new("- List all available STM32 targets", new Options { ListTargets = true, Platform =  SupportedPlatform.stm32 }),
                 new("- List all available COM ports", new Options { ListComPorts = true }),
             };
     }