Better README (#3)

* Better README

README.md

@@ -1,7 +1,8 @@
-# Finite State Machines [![PkgGoDev](https://pkg.go.dev/badge/github.com/cocoonspace/fsm)](https://pkg.go.dev/github.com/cocoonspace/fsm) [![Build Status](https://app.travis-ci.com/cocoonspace/fsm.svg?branch=master)](https://app.travis-ci.com/cocoonspace/fsm) [![Coverage Status](https://coveralls.io/repos/github/cocoonspace/fsm/badge.svg?branch=master)](https://coveralls.io/github/cocoonspace/fsm?branch=master) [![Go Report Card](https://goreportcard.com/badge/github.com/cocoonspace/fsm)](https://goreportcard.com/report/github.com/cocoonspace/fsm)
+# fsm [![PkgGoDev](https://pkg.go.dev/badge/github.com/cocoonspace/fsm)](https://pkg.go.dev/github.com/cocoonspace/fsm) [![Build Status](https://app.travis-ci.com/cocoonspace/fsm.svg?branch=master)](https://app.travis-ci.com/cocoonspace/fsm) [![Coverage Status](https://coveralls.io/repos/github/cocoonspace/fsm/badge.svg?branch=master)](https://coveralls.io/github/cocoonspace/fsm?branch=master) [![Go Report Card](https://goreportcard.com/badge/github.com/cocoonspace/fsm)](https://goreportcard.com/report/github.com/cocoonspace/fsm)
 
+Package fsm allows you to add [finite-state machines](https://en.wikipedia.org/wiki/Finite-state_machine) to your Go code.
 
-Package fsm allows you to add Finite State Machines to your code.
+States and Events are defined as int consts :
 
 ```go
 const (
@@ -11,6 +12,7 @@ const (
 
 const (
     EventFoo fsm.Event = iota
+    EventBar
 )
 
 f := fsm.New(StateFoo)
@@ -24,11 +26,35 @@ You can have custom checks or actions :
 
 ```go
 f.Transition(
-    fsm.Src(StateFoo), fsm.Check(func() bool {
+    fsm.Src(StateFoo), fsm.Check(func () bool {
         // check something
     }),
-    fsm.Call(func() {
+    fsm.Call(func () {
         // do something
     }),
 )
-```
+```
+
+Transitions can be triggered the second time an event occurs :
+
+```go
+f.Transition(
+    fsm.On(EventFoo), fsm.Src(StateFoo), fsm.Times(2),
+    fsm.Dst(StateBar),
+)
+```
+
+## Installation
+
+go get github.com/cocoonspace/fsm
+
+## Contribution guidelines
+
+Contributions are welcome, as long as:
+
+* unit tests & comments are included,
+* no external package is used.
+
+## License
+
+MIT - See LICENSE