Should the .gitattributes file be in the commit?

First of all, I recommend reading the documentation first.

It suggests either checking in the .gitattributes file at the root of your repository or inside your local .git folder here: .git/info/attributes.

The latter option will probably have the least impact (if you are the only Windows user).

With this kind of thing I tend to put the onus on whoever 'likes to be different' in the team - e.g. if all but one of the devs are using Mac's and the other is using Windows for example, it should really be up to the guy who is going against the grain to sort out. It's nothing malicious, just fair :-)

I added this:

# Set default behaviour, in case users don't have core.autocrlf set.
* text=auto

# Explicitly declare text files we want to always be normalized and converted
# to native line endings on checkout.
*.c text
*.h text

# Declare files that will always have CRLF line endings on checkout.
*.sln text eol=crlf

# Denote all files that are truly binary and should not be modified.
*.png binary
*.jpg binary

and committed it to the GitHub server. So everyone who had this fixed the problems.