Tweak README.md

Author: nobeans

README.md

@@ -1,21 +1,67 @@
-## GExcelAPI
+GExcelAPI
+=========
 
-GExcelAPI is a thin wrapper library powered by Groovy of Apache POI, not JExcelAPI.
+GExcelAPI is a thin Groovy-ish wrapper library of not JExcelAPI but Apache POI.
 
-## Usage
 
-About its usage, see a following article:
+Getting Started
+---------------
 
-* <http://nobeans-en.blogspot.jp/2011/11/gexcelapi-for-groovyist-using-ms-excel.html>
+It's difficult to read and write when using Apache POI directly.
+Especially, an identification of a cell to use an index is too complicated and ugly.
 
-and a test code:
+```groovy
+File inputFile = ...
+def book = new HSSFWorkbook(new POIFSFileSystem(new FileInputStream(inputFile)))
+def sheet = book.getSheetAt(0) // 1st sheet
+println "A1: " +  sheet.getRow(0)?.getCell((short) 0)
+println "A2: " +  sheet.getRow(1)?.getCell((short) 0)
+println "B1: " +  sheet.getRow(0)?.getCell((short) 1)
+```
 
-* <https://github.com/nobeans/gexcelapi/raw/master/src/test/groovy/org/jggug/kobo/gexcelapi/GExcelTest.groovy>
+By using GExcelAPI, you can write the above sample like this:
 
-## Code Status
+```groovy
+File inputFile = ...
+def book = GExcel.open(inputFile)
+def sheet = book[0] // 1st sheet
+println "A1: "   sheet.A1.value
+println "A2: "   sheet.A2.value
+println "B1: "   sheet.B1.value
+```
 
-* [![Build Status](https://drone.io/github.com/nobeans/gexcelapi/status.png)](https://drone.io/github.com/nobeans/gexcelapi/latest)
 
-## License
+How to get
+-----------
+
+### Grape
+
+```groovy
+@GrabResolver(name="bintray", root="http://dl.bintray.com/nobeans/maven")
+@GrabConfig(systemClassLoader=true) // necessary if you invoke it by GroovyServ
+@Grab("org.jggug.kobo:gexcelapi:0.4")
+import org.jggug.kobo.gexcelapi.GExcel
+
+// example...
+def book = GExcel.open(args[0])
+def sheet = book[0]
+println sheet.A1.value
+```
+
+
+Test as Documentation
+---------------------
+
+* <https://github.com/nobeans/gexcelapi/blob/master/src/test/groovy/org/jggug/kobo/gexcelapi/GExcelTest.groovy>
+
+
+Code Status
+-----------
+
+[![Build Status](https://travis-ci.org/nobeans/gexcelapi.svg?branch=master)](https://travis-ci.org/nobeans/gexcelapi)
+
+
+License
+-------
 
 GExcelAPI is released under the [Apache 2.0 License](http://www.apache.org/licenses/LICENSE-2.0)