Add some notes for the extended collision box impl

Signed-off-by: Joshua Castle <26531652+Kas-tle@users.noreply.github.com>

core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java

@@ -134,6 +134,11 @@ public final class BlockRegistryPopulator {
                     NbtMap tag = customBlockStates.get(i);
                     CustomBlockState blockState = customExtBlockStates.get(i);
                     customBlockStateIds.put(blockState, blockStateOrderedMap.getOrDefault(tag, -1));
+                    // At this point, we have the bedrock runtime ID for our extended collision block, as well as its custom block state
+                    // So then I think what we would prefer for the registry of the collision boxes is having the collision box be the key
+                    // That registry will be used here to check if the given CustomBlockState is an extended collision block
+                    // Then right here we can populate our final registry which maps the java runtime ID to the bedrock runtime ID of our collision block
+                    // So therefore our initial extended collision registry should map to a set of java runtime IDs
                 }
 
                 remappedVanillaIds = new int[vanillaBlockStates.size()];

core/src/main/java/org/geysermc/geyser/registry/populator/CustomBlockRegistryPopulator.java

@@ -106,6 +106,7 @@ public class CustomBlockRegistryPopulator {
                 BoxComponent extendedCollisionBox = customBlockState.block().components().extendedCollisionBox();
                 if (extendedCollisionBox != null) {
                     extendedCollisionBoxes.put(id, extendedCollisionBox);
+                    // Here and in the API, we will also need to add a method to build proper custom block data based on the extended collision box and add to customBlocks
                 }
             });
         });