Comment .gitattributes and flesh out some endings

.gitattributes

@@ -1,6 +1,15 @@
-# Text files (convert crlf > lf)
-*.bat     text
-*.cmd     text
+# This file is understood by git 1.7.2+.
+
+# Windows specific files should always be crlf on checkout
+*.bat text eol=crlf
+*.cmd text eol=crlf
+*.ps1 text eol=crlf
+
+# Check out the following as ln always for osx/linux/cygwin
+*.sh text eol=lf
+
+# Opt in the following types to always normalize line endings
+# on checkin and always use native endings on checkout.
 *.config  text
 *.cs      text diff=csharp
 *.csproj  text
@@ -11,6 +20,7 @@
 *.ps1     text
 *.sln     text
 *.tt      text
+*.txt     text
 *.xaml    text
 *.xml     text