start femu with packages

If you do not already have an instance running, start the emulator:

Start a new emulator instance:
```
ffx emu start --headless
```
When startup is complete, the emulator prints the following message and returns:

none {:.devsite-disable-click-to-copy} Logging to "{{ '<var>' }}$HOME{{ '</var>' }}/.local/share/Fuchsia/ffx/emu/instances/fuchsia-emulator/emulator.log" Waiting for Fuchsia to start (up to 60 seconds)........ Emulator is ready.
Start a package server to enable the emulator to load software packages:
```
fx serve-updates
```

最后更新: 2022 年 12 月 31 日（Saturday） 21:07 CST