[INFRA] Add a .gitattributes file to enforce line endings

[DimitriPapadopoulos]

As seen in #859.

Suggested solution documented in this comment: #859 (comment)

[Remi-Gau]

I think we discussed this a while back (can't remember where) and said that we'd cross that bridge when we get to it.

Personally ok with crossing it now.

[sappelhoff]

I think we discussed this a while back (can't remember where) and said that we'd cross that bridge when we get to it.

Thanks, that reminded me as well ... but I cannot find that issue/PR/conversation again :( if you know where it is, Remi - could you please crosslink to here?

[Remi-Gau]

Sweet baby jesus on a pogo stick: that took quite a bit of github archeology to dig that convo, but here it is (in the validator repo)

https://github.com/bids-standard/bids-validator/pull/1134#discussion_r559558156