coc: adding language regarding casual mentions of slavery (#48)

* adding language regarding casual mentions of slavery

* adding @zkat phrasing suggestion re:hardware and software design patters

Author: cjwilburn

_pages/code-of-conduct.md

@@ -37,6 +37,7 @@ Examples of unacceptable behavior by participants include:
 
   * The use of sexualized language or imagery and unwelcome sexual attention or advances, including when simulated online. The only exception to sexual topics is channels/spaces specifically for topics of sexual identity.
   * Trolling, insulting/derogatory comments, and personal or political attacks.
+  * Casual mention of slavery or indentured servitude and/or false comparisons of one's occupation or situation to slavery. Please consider using or asking about alternate terminology when referring to such metaphors in technology.
   * Public or private harassment, deliberate intimidation, or threats.
   * Publishing others' private information, such as a physical or electronic address, without explicit permission. This includes any sort of "outing" of any aspect of someone's identity without their consent.
   * Publishing screenshots or quotes, especially from identity channels, without all quoted users' *explicit* consent.