[Feature] Add browser extension to automatically start downloading main program.

At present, if the main program is not started, you will not be able to call the download through the browser extension.

Can you consider adding the following functions : When the download main program is not started, you can start the download main program through the browser extension.

The following is one of the implementations I know:

- When downloading the main program, write it into the registry and register the custom protocol.
- Wake up and download the main program by using the custom protocol in the browser.

The following Example is the browser starting VSCode:

> register.reg

```
Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CodeWebshell]
@="URL:CodeWebshell Protocol Handler"
"URL Protocol"=""

[HKEY_CLASSES_ROOT\CodeWebshell\DefaultIcon]
@="D:\\soft\\Microsoft VS Code\\Code.exe"

[HKEY_CLASSES_ROOT\CodeWebshell\shell]
[HKEY_CLASSES_ROOT\CodeWebshell\shell\open]
[HKEY_CLASSES_ROOT\CodeWebshell\shell\open\command]
@="VSCode Location"
```

> test.html

```

Test

Startup

```