Fill in some undocumented entries (#356)

* Add permutations description

* Adjust grammar

* Update description of "num_mip_levels"

* Update "atlas_tile" and "blend_frames" property

Some properties had completely incorrect titles as well, those were fixed in this commit too.

* Update JSON UI schema

* Update item schema

* Update terrain_texture schema

* Update animations schema

* Update go_home.json

* Update textures schemas

source/behavior/blocks/format/minecraft.block.json

@@ -136,14 +136,15 @@
     "permutations": {
       "type": "array",
       "title": "Permutations",
-      "description": "UNDOCUMENTED.",
+      "description": "An array of different versions of a block, allowing you to specify which components you want the block to have under certain conditions.",
       "$comment": "UNDOCUMENTED",
       "items": {
         "title": "Permutation",
-        "description": "UNDOCUMENTED.",
+        "description": "A permutation of a block, which will be applied given the condition is met.",
         "$comment": "UNDOCUMENTED",
         "type": "object",
         "additionalProperties": false,
+        "required": [ "condition" ],
         "properties": {
           "condition": {
             "title": "Condition",