license type not mentioned in headers

[thijstriemstra]

the license type should be mentioned in the (copyright) headers:

/*****************************************
This is a library for the MCP23017 and MCP23S17 I/O Port Expander
This specific header file is just for introducing the class name MCP23S17. It inherits 
everything from MCP23017, including the constructors. 
You'll find some examples including the wiring which should enable you to use the library. 
Furthermore I have added a list of commands.
You are free to use it, change it or build on it. In case you like it, it would be cool 
if you give it a star.
If you find bugs, please inform me!
Written by Wolfgang (Wolle) Ewald
https://wolles-elektronikkiste.de/port-expander-mcp23017-2?lang=en
*******************************************/

And I would minimize the extra info..

Also note that mcp23x18 is not referenced either.