[SPARK-51997] Mark nodoc to hide generated and internal classes from docs

### What changes were proposed in this pull request?

This PR aims mark `nodoc` to hide generated and internal classes from docs.

### Why are the changes needed?

Since #107, the documentation is visible here.
- https://swiftpackageindex.com/apache/spark-connect-swift/main/documentation/sparkconnect

We need to simplify the documentation to focus `Spark Connect for Swift` itself by hiding irrelevant information . For example, `Arrow`-related information will be removed eventually when we start to use the official `Apache Arrow` release.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Manual review.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #113 from dongjoon-hyun/SPARK-51997.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

Sources/SparkConnect/ArrowArray.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public protocol ArrowArrayHolder {
   var type: ArrowType { get }
   var length: UInt { get }
@@ -28,6 +29,7 @@ public protocol ArrowArrayHolder {
   var getArrowColumn: (ArrowField, [ArrowArrayHolder]) throws -> ArrowColumn { get }
 }
 
+/// @nodoc
 public class ArrowArrayHolderImpl: ArrowArrayHolder {
   public let data: ArrowData
   public let type: ArrowType
@@ -121,6 +123,7 @@ public class ArrowArrayHolderImpl: ArrowArrayHolder {
   }
 }
 
+/// @nodoc
 public class ArrowArray<T>: AsString, AnyArray {
   public typealias ItemType = T
   public let arrowData: ArrowData
@@ -160,6 +163,7 @@ public class ArrowArray<T>: AsString, AnyArray {
   }
 }
 
+/// @nodoc
 public class FixedArray<T>: ArrowArray<T> {
   public override subscript(_ index: UInt) -> T? {
     if self.arrowData.isNull(index) {
@@ -171,6 +175,7 @@ public class FixedArray<T>: ArrowArray<T> {
   }
 }
 
+/// @nodoc
 public class StringArray: ArrowArray<String> {
   public override subscript(_ index: UInt) -> String? {
     let offsetIndex = MemoryLayout<Int32>.stride * Int(index)
@@ -197,6 +202,7 @@ public class StringArray: ArrowArray<String> {
   }
 }
 
+/// @nodoc
 public class BoolArray: ArrowArray<Bool> {
   public override subscript(_ index: UInt) -> Bool? {
     if self.arrowData.isNull(index) {
@@ -208,6 +214,7 @@ public class BoolArray: ArrowArray<Bool> {
   }
 }
 
+/// @nodoc
 public class Date32Array: ArrowArray<Date> {
   public override subscript(_ index: UInt) -> Date? {
     if self.arrowData.isNull(index) {
@@ -221,6 +228,7 @@ public class Date32Array: ArrowArray<Date> {
   }
 }
 
+/// @nodoc
 public class Date64Array: ArrowArray<Date> {
   public override subscript(_ index: UInt) -> Date? {
     if self.arrowData.isNull(index) {
@@ -234,9 +242,12 @@ public class Date64Array: ArrowArray<Date> {
   }
 }
 
+/// @nodoc
 public class Time32Array: FixedArray<Time32> {}
+/// @nodoc
 public class Time64Array: FixedArray<Time64> {}
 
+/// @nodoc
 public class BinaryArray: ArrowArray<Data> {
   public struct Options {
     public var printAsHex = false
@@ -279,6 +290,7 @@ public class BinaryArray: ArrowArray<Data> {
   }
 }
 
+/// @nodoc
 public class StructArray: ArrowArray<[Any?]> {
   public private(set) var arrowFields: [ArrowArrayHolder]?
   public required init(_ arrowData: ArrowData) throws {

Sources/SparkConnect/ArrowArrayBuilder.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public protocol ArrowArrayHolderBuilder {
   func toHolder() throws -> ArrowArrayHolder
   func appendAny(_ val: Any?)

Sources/SparkConnect/ArrowBuffer.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public class ArrowBuffer {
   static let minLength: UInt = 1 << 5
   static let maxLength = UInt.max

Sources/SparkConnect/ArrowBufferBuilder.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public protocol ArrowBufferBuilder {
   associatedtype ItemType
   var capacity: UInt { get }

Sources/SparkConnect/ArrowData.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public class ArrowData {
   public let type: ArrowType
   public let buffers: [ArrowBuffer]

Sources/SparkConnect/ArrowDecoder.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public class ArrowDecoder: Decoder {
   var rbIndex: UInt = 0
   var singleRBCol: Int = 0

Sources/SparkConnect/ArrowEncoder.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public class ArrowEncoder: Encoder {
   public private(set) var builders = [String: ArrowArrayHolderBuilder]()
   private var byIndex = [String]()

Sources/SparkConnect/ArrowReader.swift

@@ -21,6 +21,7 @@ import Foundation
 let FILEMARKER = "ARROW1"
 let CONTINUATIONMARKER = -1
 
+/// @nodoc
 public class ArrowReader {  // swiftlint:disable:this type_body_length
   private class RecordBatchData {
     let schema: org_apache_arrow_flatbuf_Schema

Sources/SparkConnect/ArrowReaderHelper.swift

@@ -18,6 +18,7 @@
 import FlatBuffers
 import Foundation
 
+/// @nodoc
 private func makeBinaryHolder(
   _ buffers: [ArrowBuffer],
   nullCount: UInt

Sources/SparkConnect/ArrowSchema.swift

@@ -17,6 +17,7 @@
 
 import Foundation
 
+/// @nodoc
 public class ArrowField {
   public let type: ArrowType
   public let name: String
@@ -29,6 +30,7 @@ public class ArrowField {
   }
 }
 
+/// @nodoc
 public class ArrowSchema {
   public let fields: [ArrowField]
   public let fieldLookup: [String: Int]