Remove advancement unlocking of encyclopedia sections

With tool materials merge into a single section, only modifiers were left unlocking as tools were long since just always unlocked.
While it was a neat feature, it really did not add anything and its not worth keeping around for just modifiers.

src/main/resources/assets/tconstruct/book/encyclopedia/en_us/intro/focus.json

@@ -0,0 +1,12 @@
+{
+  "title": "Focus",
+  "text": [
+    {
+      "text": "This book is focused on tool building. Unlike other volumes like Materials and You or Mighty Smelting, it won't explain how to use the technology used in tool creation; it just lists all the optionals available assuming you have the technology."
+    },
+    {
+      "text": "If you are unsure of how to use the technology or find the resources, you will need to refer to a copy of Materials and You, Puny Smelting, Mighty Smelting, Fantastic Foundry, or Tinkers' Gadgetry.",
+      "paragraph": true
+    }
+  ]
+}

src/main/resources/assets/tconstruct/book/encyclopedia/index.json

@@ -48,8 +48,6 @@
   {
     "name": "upgrades",
     "data": "sections/upgrades.json",
-    "requirements": [ "tconstruct:smeltery/puny_smelting" ],
-    "hideWhenLocked": true,
     "icon": {
       "item": {
         "type": "forge:nbt",
@@ -63,8 +61,6 @@
   {
     "name": "defense",
     "data": "sections/defense.json",
-    "requirements": [ "tconstruct:smeltery/mighty_smelting" ],
-    "hideWhenLocked": true,
     "icon": {
       "item": {
         "type": "forge:nbt",
@@ -78,8 +74,6 @@
   {
     "name": "slotless",
     "data": "sections/slotless.json",
-    "requirements": [ "tconstruct:smeltery/puny_smelting" ],
-    "hideWhenLocked": true,
     "icon": {
       "item": {
         "type": "forge:nbt",
@@ -93,8 +87,6 @@
   {
     "name": "abilities",
     "data": "sections/abilities.json",
-    "requirements": [ "tconstruct:smeltery/mighty_smelting" ],
-    "hideWhenLocked": true,
     "icon": {
       "item": {
         "type": "forge:nbt",
@@ -131,7 +123,6 @@
   },
   {
     "name": "materials_skull",
-    "requirements": [ "tconstruct:world/tinkers_gadgetry" ],
     "data": "no-load",
     "extraData": { "tconstruct:material_tier": { "type": "tconstruct:skull", "detailed": true } },
     "icon": {

src/main/resources/assets/tconstruct/book/encyclopedia/sections/intro.json

@@ -5,8 +5,8 @@
     "data": "intro/foreward.json"
   },
   {
-    "name": "updates",
+    "name": "focus",
     "type": "mantle:text",
-    "data": "intro/updates.json"
+    "data": "intro/focus.json"
   }
 ]