[skip ci] added commment about autobuild inside vms (#3379)

docs/autobuild.sh

@@ -1,4 +1,8 @@
 #!/bin/sh
+# If you want to run this script inside a vm and save changes outside of it
+# You should upgrade watchdog library to the latest in https://github.com/gorakhargosh/watchdog
+# and add --debug-force-polling argument to shell-command
+# watchmedo shell-command --debug-force-polling --patterns="*.rst" --ignore-pattern='_build/*' --recursive --command='make html; echo "Waiting for more changes..."'
 
 echo "Waiting for you to save the docs..."
 watchmedo shell-command --patterns="*.rst" --ignore-pattern='_build/*' --recursive --command='make html; echo "Waiting for more changes..."'