Add some mud blocks

I hate this codebase so much.

overviewer_core/src/block_class.c

@@ -341,7 +341,8 @@ const mc_block_t block_class_alt_height[] = {
     block_cobbled_deepslate_slab,
     block_polished_deepslate_slab,
     block_deepslate_brick_slab,
-    block_deepslate_tile_slab};
+    block_deepslate_tile_slab,
+    block_mud_brick_slab};
 const size_t block_class_alt_height_len = COUNT_OF(block_class_alt_height);
 
 const mc_block_t block_class_nether_roof[] = {

overviewer_core/src/mc_id.h

@@ -405,6 +405,11 @@ enum mc_block_id {
     block_glow_lichen = 1119,
     block_spore_blossom = 1120,
 
+    block_mud = 1121,
+    block_packed_mud = 1122,
+    block_mud_bricks = 1123,
+    block_mud_brick_slab = 1124,
+
     // adding a gap in the numbering of walls to keep them all
     // in one numbering block starting at 1792
     // all blocks between 1792 and 2047 are considered walls

overviewer_core/src/overviewer.h

@@ -31,7 +31,7 @@
 
 // increment this value if you've made a change to the c extension
 // and want to force users to rebuild
-#define OVERVIEWER_EXTENSION_VERSION 110
+#define OVERVIEWER_EXTENSION_VERSION 111
 
 #include <stdbool.h>
 #include <stdint.h>