start to translator chinese to English

en/src/1.2/sqrt.go

@@ -0,0 +1,11 @@
+// 章节 1.2
+// $GOPATH/src/mymath/sqrt.go
+package mymath
+
+func Sqrt(x float64) float64 {
+	z := 0.0
+	for i := 0; i < 1000; i++ {
+		z -= (z*z - x) / (2 * x)
+	}
+	return z
+}