made nice category icons for the book

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/collecting.json

@@ -1,6 +1,6 @@
 {
     "name": "Collecting Aura",
     "description": "To be able to make use of the $(aura) in the world, one must first find a way to handle it reasonably. Converting it into a storable form $(italics)(no, not liquids)$() might prove somewhat difficult, but this category will provide guidance.",
-    "icon": "naturesaura:eye",
+    "icon": "naturesaura:textures/gui/patchouli/categories/collecting.png",
     "sortnum": 10
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/creating.json

@@ -1,6 +1,6 @@
 {
     "name": "Creating Aura",
     "description": "The finity of $(aura) in the world can be troubling to think about, because once it is drained, it seems like it is not restorable. That, however, is not the case: This category houses explanations for how to create $(aura) using different techniques.",
-    "icon": "naturesaura:ancient_sapling",
+    "icon": "naturesaura:textures/gui/patchouli/categories/creating.png",
     "sortnum": 18
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/effects.json

@@ -1,6 +1,6 @@
 {
     "name": "Aura Imbalance",
     "description": "Draining $(aura) from the world or adding more of it is what is called $(thing)Aura Imbalance$() - and it can have both positive and negative effects. Those are listed in this category.",
-    "icon": "naturesaura:decayed_leaves",
+    "icon": "naturesaura:textures/gui/patchouli/categories/effects.png",
     "sortnum": 20
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/intro.json

@@ -1,6 +1,6 @@
 {
     "name": "Introduction",
     "description": "For one who has never made use of the power of $(aura) before, it might be a daunting task to get a hold of.$(br2)These introductory entries will give a brief overview of how, why and where it works.",
-	"icon": "minecraft:writable_book",
+    "icon": "naturesaura:textures/gui/patchouli/categories/intro.png",
     "sortnum": 0
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/items.json

@@ -1,6 +1,6 @@
 {
     "name": "Natural Items",
     "description": "The thought of nature might lead you to the beach, the forest, or a plain, but sometimes, it might lead you to items and accessories that are strongly intertwined with nature itself. In this category, such items can be found.",
-    "icon": "naturesaura:infused_iron_pickaxe",
+    "icon": "naturesaura:textures/gui/patchouli/categories/items.png",
     "sortnum": 25
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/practices.json

@@ -1,6 +1,6 @@
 {
     "name": "Natural Practices",
     "description": "Related to $(aura), but not necessarily to its collection and storage, can be other practices that might prove beneficial in the long run. This category provides information on what practices exist and how to execute them.",
-    "icon": "naturesaura:gold_powder",
+    "icon": "naturesaura:textures/gui/patchouli/categories/practices.png",
     "sortnum": 5
 }

src/main/resources/assets/naturesaura/patchouli_books/book/en_us/categories/using.json

@@ -1,6 +1,6 @@
 {
     "name": "Harnessing Aura",
     "description": "When collecting $(aura) from the world, an instinctive question for any human to ask would be $(italic)\"How can one make use of this?\"$() This category houses entries that will explain just that.",
-    "icon": "naturesaura:aura_cache",
+    "icon": "naturesaura:textures/gui/patchouli/categories/using.png",
     "sortnum": 15
 }