Added brief coding conventions - these may not be complete.

By: Warren <evilseph@unaligned.org>

paper-api/README.md

@@ -3,6 +3,16 @@ Bukkit
 
 A Minecraft Server API.
 
+Coding Conventions
+-----------
+
+We generally follow the Sun/Oracle coding standards.
+No tabs; use 4 spaces instead.
+No trailing whitespaces.
+No 80 column limit or midstatement newlines.
+
+Follow the above conventions if you want your pull requests accepted.
+
 Compilation
 -----------