[optimize] rtthread.md

Author: SummerGift

docs/spec-librarys/rtthread.md

@@ -10,25 +10,14 @@
 #### rtthread.is_preempt_thread()  
 返回是否是可抢占线程。
 
-#### rtthread.stacks_analyze()  
-返回当前系统线程和栈使用信息。
-
 ### 示例
 
 ```
 >>> import rtthread
 >>> 
->>> rtthread.is_preempt_thread()       # determine if code is running in a preemptible thread
+>>> rtthread.is_preempt_thread()       # determine if it's a preemptible thread
 True
 >>> rtthread.current_tid()             # current thread id
 268464956
->>> rtthread.stacks_analyze()          # show thread information
-thread     pri  status      sp     stack size max used left tick  error
----------- ---  ------- ---------- ----------  ------  ---------- ---
-elog_async  31  suspend 0x000000a8 0x00000400    26%   0x00000003 000
-tshell      20  ready   0x00000260 0x00001000    39%   0x00000003 000
-tidle       31  ready   0x00000070 0x00000100    51%   0x0000000f 000
-SysMonitor  30  suspend 0x000000a4 0x00000200    32%   0x00000005 000
-timer        4  suspend 0x00000080 0x00000200    25%   0x00000009 000
 >>> 
 ```