Update min node version in README (#986)

README.md

@@ -19,7 +19,7 @@
 Pynecone requires the following to get started:
 
 -   Python 3.7+
--   [Node.js 12.22.0+](https://nodejs.org/en/) (Don't worry, you won’t have to write any JavaScript!)
+-   [Node.js 16.6.0+](https://nodejs.org/en/) (Don't worry, you won’t have to write any JavaScript!)
 
 ```
 $ pip install pynecone