update cobble groups to cracky

nodes.lua

@@ -340,7 +340,7 @@ minetest.register_node("caverealms:stone_with_moss", {
 	description = "Cave Stone with Moss",
 	tiles = {"default_cobble.png^caverealms_moss.png", "default_cobble.png", "default_cobble.png^caverealms_moss_side.png"},
 	is_ground_content = true,
-	groups = {crumbly=3},
+	groups = {cracky=3},
 	drop = 'default:cobble',
 	sounds = default.node_sound_dirt_defaults({
 		footstep = {name="default_grass_footstep", gain=0.25},
@@ -364,7 +364,7 @@ minetest.register_node("caverealms:stone_with_algae", {
 	description = "Cave Stone with Algae",
 	tiles = {"default_cobble.png^caverealms_algae.png", "default_cobble.png", "default_cobble.png^caverealms_algae_side.png"},
 	is_ground_content = true,
-	groups = {crumbly=3},
+	groups = {cracky=3},
 	drop = 'default:cobble',
 	sounds = default.node_sound_dirt_defaults({
 		footstep = {name="default_grass_footstep", gain=0.25},
@@ -381,7 +381,7 @@ minetest.register_node("caverealms:stone_with_salt", {
 	drawtype = "glasslike",
 	sunlight_propagates = true,
 	is_ground_content = true,
-	groups = {crumbly=3},
+	groups = {cracky=3},
 	sounds = default.node_sound_glass_defaults(),
 })
 
@@ -390,7 +390,7 @@ minetest.register_node("caverealms:hot_cobble", {
 	description = "Hot Cobble",
 	tiles = {"caverealms_hot_cobble.png"},
 	is_ground_content = true,
-	groups = {crumbly=2, hot=1},
+	groups = {cracky=2, hot=1},
 	damage_per_second = 1,
 	light_source = 3,
 	sounds = default.node_sound_stone_defaults({
@@ -403,7 +403,7 @@ minetest.register_node("caverealms:glow_obsidian", {
 	description = "Glowing Obsidian",
 	tiles = {"caverealms_glow_obsidian.png"},
 	is_ground_content = true,
-	groups = {crumbly=1},
+	groups = {cracky=1},
 	light_source = 7,
 	sounds = default.node_sound_stone_defaults({
 		footstep = {name="default_stone_footstep", gain=0.25},
@@ -415,7 +415,7 @@ minetest.register_node("caverealms:glow_obsidian_2", {
 	description = "Hot Glow Obsidian",
 	tiles = {"caverealms_glow_obsidian2.png"},
 	is_ground_content = true,
-	groups = {crumbly=1, hot=1},
+	groups = {cracky=1, hot=1},
 	damage_per_second = 1,
 	light_source = 9,
 	sounds = default.node_sound_stone_defaults({