update README.

README.md

@@ -17,11 +17,13 @@
 ## Overview
 
 ### Installation
+
 ```bash
 npm install @solvprotocol/erc-3525@latest
 ```
 
 ### Usage
+Once installed, you can use the contracts in the library by importing them:
 
 ```solidity
 pragma solidity ^0.8.9;
@@ -36,6 +38,8 @@ constructor()
 }
 ```
 
+To keep your system secure, you should always use the installed code as-is, and neither copy-paste it from online sources nor modify it yourself.
+
 ## Learn More
 
 [ERC-3525 White Paper](https://whitepaper.sftlabs.io/SFT%20Whitepaper.pdf)