feat: Working on node builder

Sources/CliDoc/Modifiers/Style.swift

@@ -0,0 +1,41 @@
+import Rainbow
+
+public extension NodeRepresentable {
+  @inlinable
+  func style(_ styles: Style...) -> any NodeRepresentable {
+    modifier(StyleModifier(styles: styles))
+  }
+
+  @inlinable
+  func style(_ styles: [Style]) -> any NodeRepresentable {
+    modifier(StyleModifier(styles: styles))
+  }
+}
+
+public extension NodeModifier {
+  @inlinable
+  static func style(_ styles: Style...) -> Self where Self == AnyNodeModifier {
+    .init(StyleModifier(styles: styles))
+  }
+
+  @inlinable
+  static func style(_ styles: [Style]) -> Self where Self == AnyNodeModifier {
+    .init(StyleModifier(styles: styles))
+  }
+}
+
+@usableFromInline
+struct StyleModifier: NodeModifier, @unchecked Sendable {
+  @usableFromInline
+  let styles: [Style]
+
+  @usableFromInline
+  init(styles: [Style]) {
+    self.styles = styles
+  }
+
+  @usableFromInline
+  func render(_ node: any NodeRepresentable) -> any NodeRepresentable {
+    styles.reduce(node.render()) { $0.applyingStyle($1) }
+  }
+}