update doc.go

doc.go

@@ -5,20 +5,18 @@ A Parser for PHP written in Go
 Features:
 
 	* Fully support PHP5 and PHP7 syntax
-
 	* Abstract syntax tree representation
-
 	* Traversing AST
 
-Install
+Install:
 
 	go get github.com/z7zmey/php-parser
 
-CLI dumper
+CLI dumper:
 
 	$GOPATH/bin/php-parser -php5 /path/to/file/or/dir
 
-Package usage example
+Package usage example:
 
 	package main