core: added docs differences warning

docs/examples/index.md

@@ -182,3 +182,11 @@ img.qr-code {
 }
 ```
 
+## Differences between acpatterns-js and acpatterns.com
+
+If you read in a file and the fields aren't the same between acnl files
+generated between acpatterns.com and acpatterns-js, this library uses field
+limitations based on in-game limits, whereas the internal library at
+acpatterns.com uses file-format based limits.
+
+e.g. ACNL only allows villager names to be 8 characters, but the file-format allows for 9 (not counting null termination). This library obeys the 8 character limit set by the developers of the game for safety.