Added 'extern "C"' to FreeRTOS-CLI header file. (#674)

Co-authored-by: JD Scott <jscott@hotstart.com>

FreeRTOS-Plus/Source/FreeRTOS-Plus-CLI/FreeRTOS_CLI.h

@@ -28,6 +28,12 @@
 #ifndef COMMAND_INTERPRETER_H
 #define COMMAND_INTERPRETER_H
 
+/* *INDENT-OFF* */
+#ifdef __cplusplus
+    extern "C" {
+#endif
+/* *INDENT-ON* */
+
 /* The prototype to which callback functions used to process command line
 commands must comply.  pcWriteBuffer is a buffer into which the output from
 executing the command can be written, xWriteBufferLen is the length, in bytes of
@@ -89,6 +95,12 @@ char *FreeRTOS_CLIGetOutputBuffer( void );
  */
 const char *FreeRTOS_CLIGetParameter( const char *pcCommandString, UBaseType_t uxWantedParameter, BaseType_t *pxParameterStringLength );
 
+/* *INDENT-OFF* */
+#ifdef __cplusplus
+    }
+#endif
+/* *INDENT-ON* */
+
 #endif /* COMMAND_INTERPRETER_H */