Add Ink Mixer and optional JEI writing guides

src/main/resources/data/rivencraft/loot_table/blocks/ink_mixer.json

@@ -0,0 +1,4 @@
+{
+  "type": "minecraft:block",
+  "pools": [{ "rolls": 1, "entries": [{ "type": "minecraft:item", "name": "rivencraft:ink_mixer" }] }]
+}

src/main/resources/data/rivencraft/recipe/ink_mixer.json

@@ -0,0 +1,11 @@
+{
+  "type": "minecraft:crafting_shaped",
+  "category": "misc",
+  "pattern": ["S S", "SVS", "PSP"],
+  "key": {
+    "S": { "item": "minecraft:stone" },
+    "V": { "item": "minecraft:glass_bottle" },
+    "P": { "tag": "minecraft:planks" }
+  },
+  "result": { "id": "rivencraft:ink_mixer", "count": 1 }
+}