virtual environment policy

还没有人认领这个 Issue。

May I suggest clarifying what the installation procedure is when working with several environments?

Should ipympl be installed in the environment where jupyter resides or in the environment where it will be used?

Similar for the labextension install commands?

I have jupyter installed on a separate pyenv (based on kernel 3.7.5) that is made global.
When creating a new environment where I want to use `%pylab widget`, I need to run:

```bash
pyenv virtualenv 3.7.5 test-ipympl
pyenv activate test-ipympl
pip install ipykernel
ipython kernel install --use --name="test-ipympl"
pip install matplotlib
pip install ipympl
```

Then I need to refresh the browser and restart any kernel running on `test-ipympl` environment

Is this the correct way to do it?

审查 issue 中描述的安装流程，分离 Jupyter 环境和 kernel 环境，以及 labextension 安装命令。确认 ipympl 支持的设置，并记录所需的命令以及重启或刷新步骤，以便用户无需猜测即可在单独的环境中安装它。

由索引模型根据 Issue 内容生成。