Add .gitattribute to help Github Linguist to correctly indentify Verilog.

[secworks]

Aloha!

According to Github, this project is partially written in the formal theorem prover language Coq.
https://en.wikipedia.org/wiki/Coq

The files in question are:

• shift_reg/piso.v
• shift_reg/sipo.v

They are clearly not Coq-files, but nice and normal Verilog files. The problem is that Github has a parser called Linguist
https://github.com/github/linguist

There has been a number of issues opened for Linguist related to misinterpreting Verilog as Coq. But so far it has not been fixed. A solution to this is to add a .gitattribute file to the repo. The file can simply contain one line:

*.v linguist-language=Verilog

There is a copy in my aes core repo you can copy:
https://github.com/secworks/aes/blob/master/.gitattributes