update readme section

updatedshmup.p8

@@ -1464,21 +1464,10 @@ of a collision or move, it will
 itself be move()d before it is
 drawn.
 
-don't modify a list while it's
-being iterated. ships that want
-to create ships and bullets
-that want to create bullets
-need to create an event to
-do this (which will run before
-the ship and bullet phases of
-the next frame). events that
-want to create events add to
-new_events, rather than events.
-
 data-driven items
 =================
-guns and bullets both allow the most
-common behaviors to be
+guns and bullets both allow the
+most common behaviors to be
 expressed with data alone.
 ships only need a movement
 algorithm expressed.
@@ -1821,21 +1810,6 @@ intangibles do not prevent the
 level from ending. like bullets
 and ships, if :move returns
 true, they are dropped.
-
-weird coding conventions
-========================
-
- * i am inconsistent between
-   including underscores or not
-   (sorry)
- * a triple underscore prefix
-   is used for fields created
-   by invasive algorithms
-   (those algorithms that
-   modify the items they're
-   given to perform some kind
-   of bookkeeping)
-
 ]]
 -->8
 -- standard events