Trivial: update git attributes for Makefile
* Update .gitattributes for Go files
Mark go source files as text, with LF line ending.
Set git diff language mode for `*.go` files to `golang`
* Add .gitattributes entry for Makefiles
-*.go whitespace=trailing-space,space-before-tab,indent-with-non-tab
-go.mod whitespace=trailing-space,space-before-tab,indent-with-non-tab
+*.go text eol=lf whitespace=trailing-space,space-before-tab,indent-with-non-tab diff=golang
+go.mod text eol=lf whitespace=trailing-space,space-before-tab,indent-with-non-tab
+go.sum text eol=lf whitespace=trailing-space,space-before-tab,indent-with-non-tab
+Makefile text eol=lf whitespace=trailing-space,space-before-tab,indent-with-non-tab
