Add Legacy-style symbol portfolios (#92)

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -22,6 +22,9 @@
   "item.rivencraft.page.unresolved": "Unresolved Symbol Page",
   "item.rivencraft.notebook": "Notebook",
   "item.rivencraft.collation_folder": "Collation Folder",
+  "item.rivencraft.symbol_portfolio": "Symbol Portfolio",
+  "item.rivencraft.symbol_portfolio.named": "%s Portfolio",
+  "item.rivencraft.symbol_portfolio.volume": "%s Portfolio %s/%s",
   "item.rivencraft.sealed_notebook": "Sealed Notebook",
   "block.rivencraft.link_modifier": "Link Modifier",
   "container.rivencraft.link_modifier": "Link Modifier",

src/main/resources/assets/rivencraft/models/item/symbol_portfolio.json

@@ -0,0 +1,4 @@
+{
+  "parent": "minecraft:item/generated",
+  "textures": { "layer0": "rivencraft:item/symbol_portfolio" }
+}