update docs

Signed-off-by: Nshawn_he <shawn.he@huawei.com>

en/application-dev/reference/native-apis/trace_8h.md

+# trace.h
+
+
+## Overview
+
+Defines APIs of the HiTraceMeter module for performance trace.
+
+Example
+
+Synchronous time slice trace event:
+
+  
+```
+OH_HiTrace_StartTrace("hitraceTest");
+OH_HiTrace_FinishTrace();
+```
+
+Output:
+
+  
+```
+<...>-1668 (----—) [003] .... 135.059377: tracing_mark_write: B|1668|H:hitraceTest
+<...>-1668 (----—) [003] .... 135.059415: tracing_mark_write: E|1668|
+```
+
+Asynchronous time slice trace event:
+
+  
+```
+OH_HiTrace_StartAsyncTrace("hitraceTest", 123);
+OH_HiTrace_FinishAsyncTrace("hitraceTest", 123);
+```
+
+Output:
+
+  
+```
+<...>-2477 (----—) [001] .... 396.427165: tracing_mark_write: S|2477|H:hitraceTest 123
+<...>-2477 (----—) [001] .... 396.427196: tracing_mark_write: F|2477|H:hitraceTest 123
+```
+
+Integer value trace event:
+
+  
+```
+OH_HiTrace_CountTrace("hitraceTest", 500);
+```
+
+Output:
+
+  
+```
+<...>-2638 (----—) [002] .... 458.904382: tracing_mark_write: C|2638|H:hitraceTest 500
+```
+
+**Since**
+
+10
+
+**Related Modules**
+
+[Hitrace](_hitrace.md)
+
+
+## Summary
+
+
+### Functions
+
+| Name| Description| 
+| -------- | -------- |
+| [OH_HiTrace_StartTrace](_hitrace.md#oh_hitrace_starttrace) (const char \*name) | Marks the start of a synchronous trace.| 
+| [OH_HiTrace_FinishTrace](_hitrace.md#oh_hitrace_finishtrace) (void) | Marks the end of a synchronous trace.| 
+| [OH_HiTrace_StartAsyncTrace](_hitrace.md#oh_hitrace_startasynctrace) (const char \*name, int32_t taskId) | Marks the start of an asynchronous trace.| 
+| [OH_HiTrace_FinishAsyncTrace](_hitrace.md#oh_hitrace_finishasynctrace) (const char \*name, int32_t taskId) | Marks the end of an asynchronous trace.| 
+| [OH_HiTrace_CountTrace](_hitrace.md#oh_hitrace_counttrace) (const char \*name, int64_t count) | Traces the value change of an integer variable based on its name.|