!5989 Add a note for summary only supports linux systems

Merge pull request !5989 from ougongchang/linux_support

mindspore/train/callback/_summary_collector.py

@@ -68,6 +68,7 @@ class SummaryCollector(Callback):
         1. Multiple SummaryCollector instances in callback list are not allowed.
         2. Not all information is collected at the training phase or at the eval phase.
         3. SummaryCollector always record the data collected by the summary operator.
+        4. SummaryCollector only supports Linux systems.
 
     Args:
         summary_dir (str): The collected data will be persisted to this directory.

mindspore/train/summary/summary_record.py

@@ -72,6 +72,7 @@ class SummaryRecord:
         1. Make sure to close the SummaryRecord at the end, otherwise the process will not exit.
            Please see the Example section below to learn how to close properly in two ways.
         2. Only one SummaryRecord instance is allowed at a time, otherwise it will cause data writing problems.
+        3. SummaryRecord only supports Linux systems.
 
     Args:
         log_dir (str): The log_dir is a directory location to save the summary.