Include line about libre != gratis

Author: danielbachhuber

index.md

@@ -131,6 +131,8 @@ For bug reports, please review [best practices for submitting a bug report](http
 
 Please do not ask support questions on Twitter. Twitter isn't an acceptable venue for support because: 1) it's hard to hold conversations in under 140 characters, and 2) Twitter isn't a place where someone with your same question can search for an answer in a prior conversation.
 
+Remember, libre != gratis; the open source license grants you the freedom to use and modify, but not commitments of other people's time. Please be respectful, and set your expectations accordingly.
+
 ## Extending
 
 A **command** is an atomic unit of WP-CLI functionality. `wp plugin install` ([doc](https://wp-cli.org/commands/plugin/install/)) is one command. `wp plugin activate` ([doc](https://wp-cli.org/commands/plugin/activate/)) is another.