Update README.md

Author: longxinH

README.md

@@ -3,7 +3,7 @@ XHProf is a function-level hierarchical profiler for PHP and has a simple HTML b
 
 This version supports PHP7
 
-#Installation
+# Installation
 ```
 git clone https://github.com/longxinH/xhprof.git ./xhprof
 cd xhprof/extension/
@@ -12,15 +12,15 @@ cd xhprof/extension/
 make && sudo make install
 ```
 
-####configuration add to your php.ini
+#### configuration add to your php.ini
 ```
 [xhprof]
 extension = xhprof.so
 xhprof.output_dir = /tmp/xhprof
 ```
 
-#新增
-####pdo占位符转换
+# 新增
+#### pdo占位符转换
 pdo预处理占位符将会转换成实际的参数，更好的掌握mysql执行消耗(只用做xhprof记录，不改变程序执行过程)
 ```php
 $_sth = $db->prepare("SELECT * FROM user where userid = :id and username = :name");
@@ -31,21 +31,21 @@ $_sth = $db->prepare("SELECT * FROM user where userid = ?");
 $_sth->execute([1]);
 $data2 = $_sth->fetch();
 ```
-#####xhprof记录数据
+##### xhprof记录数据
 ```
 PDOStatement::execute#SELECT * FROM user where userid = 1 and username = admin
 
 PDOStatement::execute#SELECT * FROM user where userid = 1
 ```
 
-####curl地址记录
+#### curl地址记录
 ```php
 $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL, "http://www.baidu.com");
 $output = curl_exec($ch);
 curl_close($ch);
 ```
-#####xhprof记录数据
+##### xhprof记录数据
 ```
 curl_exec#http://www.baidu.com
 ```