Infrastructure: Fix .gitattributes typo eof -> eol. Also update README

Add to README: git config --global core.fileMode false

.gitattributes

@@ -8,10 +8,10 @@
 *.txt text
 
 # source code can be native and normalized, but simpler if lf everywhere; will try that way
-*.h text eof=lf
-*.c text eof=lf
-*.cpp text eof=lf
-*.y text eof=lf
-*.out text eof=lf
-*.conf text eof=lf
-*.err text eof=lf
+*.h text eol=lf
+*.c text eol=lf
+*.cpp text eol=lf
+*.y text eol=lf
+*.out text eol=lf
+*.conf text eol=lf
+*.err text eol=lf