Updated README

README.md

@@ -1,11 +1,25 @@
 #Enumer
-
 Enumer generates Go code to get string names from enum values and viceversa.
 It is a fork of [Rob Pike’s Stringer tool](https://godoc.org/golang.org/x/tools/cmd/stringer) 
 but adding a *"string to enum value"* method to the generated code.
 
-For example, if we have an enum type called `Pill`, executing `enumer -type=Pill` will generate two methods:
+This is useful when you need to read enum values from the command line arguments, from a configuration file, 
+from a REST API request... In short, from those places where using the real enum value (an integer) would 
+be almost meaningless or hard to trace or use by a human
 
+For example, if we have an enum type called `Pill`,
+```
+type Pill int
+
+const (
+	Placebo Pill = iota
+	Aspirin
+	Ibuprofen
+	Paracetamol
+	Acetaminophen = Paracetamol
+)
+```
+executing `enumer -type=Pill` will generate a new file with two methods:
 ```
 func (i Pill) String() string {
     //...
@@ -15,5 +29,25 @@ func PillString(s string) (Pill, error) {
     //...
 }
 ```
+From now on, we can:
+```
+// Convert any Pill value to string
+var aspirinString string = Aspirin.String()
+// (or use it in any place where a Stringer is accepted)
+fmt.Println("I need ", Paracetamol) // Will print "I need Paracetamol"
 
-For more information on how to use, please go to the [Stringer docs](https://godoc.org/golang.org/x/tools/cmd/stringer) 
+// Convert a string with the enum name to the corresponding enum value
+pill, err := PillString("Ibuprofen")
+if err != nil {
+    fmt.Println("Unrecognized pill: ", err)
+    return
+}
+// Now pill == Ibuprofen
+```
+
+The generated code is exactly the same as the Stringer tool plus the `<Type>String` method, so you can use
+**Enumer** where you are already using **Stringer** without any code change.
+
+## How to use
+The usage of Enumer is the same as Stringer, no changes were introduced.
+For more information please refer to the [Stringer docs](https://godoc.org/golang.org/x/tools/cmd/stringer)