Add font infrastructure

Sources/SwiftUIMath/Internal/Font/Table.swift

@@ -0,0 +1,39 @@
+import Foundation
+
+extension Math {
+  struct Table: Codable, Sendable {
+    struct Assembly: Codable, Sendable {
+      struct Part: Codable, Sendable {
+        let advance: Int
+        let endConnector: Int
+        let extender: Bool
+        let glyph: String
+        let startConnector: Int
+      }
+
+      let italic: Int
+      let parts: [Part]
+    }
+
+    private enum CodingKeys: String, CodingKey {
+      case version
+      case accents
+      case constants
+      case italic
+      case hVariants = "h_variants"
+      case vVariants = "v_variants"
+      case vAssembly = "v_assembly"
+    }
+
+    let version: String
+
+    let accents: [String: Int]
+    let constants: [String: Int]
+    let italic: [String: Int]
+
+    let hVariants: [String: [String]]
+    let vVariants: [String: [String]]
+
+    let vAssembly: [String: Assembly]
+  }
+}