fix nnictl doc link (#4807)

.github/ISSUE_TEMPLATE/bug-report.md

@@ -33,7 +33,7 @@ about: Report an issue or question while using nni instance (deployment).
 <!--
 Where can you find the log files:
 LOG: https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/HowToDebug.md#experiment-root-director
-STDOUT/STDERR: https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/Nnictl.md#nnictl%20log%20stdout
+STDOUT/STDERR: https://nni.readthedocs.io/en/stable/reference/nnictl.html#nnictl-log-stdout
 -->
 
 

.github/ISSUE_TEMPLATE/studentProgram.md

@@ -40,5 +40,5 @@ about: NNI Student Program China issue template on Github
 **Log message / 日志信息 :**
  - [nnimanager.log and dispatcher.log](https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/HowToDebug.md#experiment-root-directory) : 
 
- - [nnictl stdout and stderr](https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/Nnictl.md#nnictl%20log%20stdout) : 
+ - [nnictl stdout and stderr](https://nni.readthedocs.io/en/stable/reference/nnictl.html#nnictl-log-stdout) : 
 

nni/tools/nnictl/launcher.py

@@ -92,7 +92,7 @@ def create_experiment(args):
     exp.start(port, debug, run_mode)
 
     _logger.info(f'To stop experiment run "nnictl stop {exp.id}" or "nnictl stop --all"')
-    _logger.info('Reference: https://nni.readthedocs.io/en/stable/Tutorial/Nnictl.html')
+    _logger.info('Reference: https://nni.readthedocs.io/en/stable/reference/nnictl.html')
 
 def resume_experiment(args):
     exp_id = args.id