add 04.2.md translate for ch 4.2

eBook/examples/chapter_4/gotemplate.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+   “fmt”
+)
+
+const c = “C”
+
+var v int = 5
+
+type T struct{}
+
+func init() { // initialization of package
+}
+
+func main() {
+    var a int
+    Func1()
+    // ...
+    fmt.Println(a)
+}
+
+func (t T) Method1() {
+    //...
+}
+
+func Func1() { // exported function Func1
+    //...
+}