Include instruction to install Python typing module
I don't know enough about Python environments to be able to say if this is a universal requirement, but on OS X, I had to install `typing` to get `:LanguageClientStart` to succeed.
Obviously you need [neovim](https://github.com/neovim/neovim#install-from-package)!
-# 2. Install python-neovim
-
+# 2. Install python modules
+## python-neovim
Run following command to install neovim python plugin host:
```
sudo pip3 install --upgrade neovim
```
+## typing
+_Note: Already included in Python version 3.6.0 and later_.
+
+Run following command to install `typing` module:
+```
+sudo pip3 install --upgrade typing
+```
+
# 3. Install this plugin
Choose steps matching your plugin manager.
