add usage demo in readme

README.md

@@ -1,3 +1,68 @@
 # dcard-spider
 [![Build Status](https://travis-ci.org/leVirve/dcard-spider.svg?branch=master)](https://travis-ci.org/leVirve/dcard-spider)
-[![Coverage Status](https://coveralls.io/repos/github/leVirve/dcard-spider/badge.svg?branch=master)](https://coveralls.io/github/leVirve/dcard-spider?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/leVirve/dcard-spider/badge.svg?branch=master)](https://coveralls.io/github/leVirve/dcard-spider?branch=master)
+
+# Usage
+## Basic
+
+```python
+# demo.py
+
+from dcard import Dcard
+
+
+if __name__ == '__main__':
+    dcard = Dcard()
+
+    ''' 取得看板資訊 (metadata)，可用參數`no_school`調整是否取得學校看版內容 '''
+    forums = dcard.forums.get()
+    forums = dcard.forums.get(no_school=True)
+
+    print(len(forums))
+
+    ''' 取得看板文章資訊 (metadata)，一頁有30篇文章，可用`pages`指定頁數數量
+        文章排序有兩種選擇: 'new' / 'popular'
+    '''
+    ariticle_metas = dcard.forums('funny').get_metas(pages=5, sort='new')
+    ariticle_metas = dcard.forums('funny').get_metas(pages=1, sort='popular')
+
+    print(len(ariticle_metas))
+
+    ''' 取得文章詳細資訊 (全文、引用連結、所有留言)
+        提供一次取得 單篇/多篇文章
+    '''
+    # 放入 文章編號/單一meta資訊 => return 單篇文章
+    article = dcard.posts(224341009).get()
+    article = dcard.posts(ariticle_metas[0]).get()
+
+    # 放入 複數文章編號/多個meta資訊 => return 一串文章
+    ids = [meta['id'] for meta in ariticle_metas]
+    articles = dcard.posts(ids).get()
+    articles = dcard.posts(ariticle_metas).get()
+
+```
+
+## Advanced
+
+```python
+from dcard import Dcard
+
+
+def collect_ids(metas):
+    return [meta['id'] for meta in metas]
+
+
+if __name__ == '__main__':
+    dcard = Dcard()
+
+    ''' 提供自定義 callback function 做在接收回傳值前做處理 '''
+    ids = dcard.forums('funny').get_metas(pages=5, callback=collect_ids)
+    print(len(ids))
+
+    ''' 文章提供 content, links, comments 三個參數
+        可選擇略過部分不需要的資訊，加快爬蟲速度
+    '''
+    articles = dcard.posts(ids).get(comments=False, links=False)
+    print(len(articles))
+
+```

spider.py

@@ -15,6 +15,6 @@ def collect_ids(metas):
     print(len(ids))
 
     t = time.time()
-    articles = dcard.posts(ids[:15]).get(comments=False)
+    articles = dcard.posts(ids).get(comments=False, links=False)
     print('{:.5f}'.format(time.time() - t))
     print(len(articles))