Use tabs as the canonical source indentation in git

Space conversion is done during generation only. Fixes #192

examples/recursion/recursion.go

@@ -9,12 +9,12 @@ import "fmt"
 // This `fact` function calls itself until it reaches the
 // base case of `fact(0)`.
 func fact(n int) int {
-    if n == 0 {
-        return 1
-    }
-    return n * fact(n-1)
+	if n == 0 {
+		return 1
+	}
+	return n * fact(n-1)
 }
 
 func main() {
-    fmt.Println(fact(7))
+	fmt.Println(fact(7))
 }