[SPARK-52075] Add Examples.md

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

This PR aims to add `Examples.md` to `Documentation.docc` directory in order to provide an overview documentation of all examples.

### Why are the changes needed?

Currently, `GettingStarted.md` is visible here.
- https://swiftpackageindex.com/apache/spark-connect-swift/main/documentation/sparkconnect/gettingstarted

`Examples.md` will be visible in the following link.
- https://swiftpackageindex.com/apache/spark-connect-swift/main/documentation/sparkconnect/examples

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

No, this is a doc-only change.

### How was this patch tested?

Manual review.

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

No.

Closes #133 from dongjoon-hyun/SPARK-52075.

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

Author: dongjoon-hyun

Sources/SparkConnect/Documentation.docc/Examples.md

@@ -0,0 +1,137 @@
+# Spark Connect Swift Examples
+
+This document provides an overview of the example applications inside [Examples](https://github.com/apache/spark-connect-swift/tree/main/Examples) directory. These examples demonstrate how to use Spark Connect Swift to interact with Apache Spark in different contexts.
+
+## Prepare Spark Connect Server
+
+Start a Spark Connect Server:
+
+```bash
+docker run -it --rm -p 15002:15002 apache/spark:4.0.0-preview2 bash -c "/opt/spark/sbin/start-connect-server.sh --wait -c spark.log.level=ERROR"
+```
+
+## Basic Application Example
+
+The basic application example demonstrates fundamental operations with Apache Spark Connect, including:
+- Connecting to a Spark server
+- Creating and manipulating tables with SQL
+- Using DataFrame operations
+- Reading and writing data in the ORC format
+
+### Key Features
+- SQL execution for table operations
+- DataFrame transformations with filter operations
+- Data persistence with ORC format
+- Basic session management
+
+### How to Run
+
+Build and run the application:
+
+```bash
+# Using Docker
+docker build -t apache/spark-connect-swift:app .
+docker run -it --rm -e SPARK_REMOTE=sc://host.docker.internal:15002 apache/spark-connect-swift:app
+
+# From source code
+swift run
+```
+
+## Pi Calculation Example
+
+The Pi calculation example shows how to use Spark Connect Swift for computational tasks by calculating an approximation of π (pi) using the Monte Carlo method.
+
+### Key Features
+- Command-line argument handling
+- Mathematical computations with Spark
+- Random number generation
+- Filtering and counting operations
+
+### How to Run
+
+Build and run the application:
+
+```bash
+# Using Docker
+docker build -t apache/spark-connect-swift:pi .
+docker run --rm -e SPARK_REMOTE=sc://host.docker.internal:15002 apache/spark-connect-swift:pi
+
+# From source code
+swift run
+```
+
+## Streaming Example
+
+The streaming example demonstrates how to process streaming data using Spark Connect Swift client, specifically for counting words from a network socket stream.
+
+### Key Features
+- Stream processing with Spark Connect
+- Network socket data source
+- Word counting with string operations
+- Real-time console output
+
+### How to Run
+
+Start a Netcat server as the data source:
+
+```bash
+nc -lk 9999
+```
+
+Build and run the application:
+
+```bash
+# Using Docker
+docker build -t apache/spark-connect-swift:stream .
+docker run --rm -e SPARK_REMOTE=sc://host.docker.internal:15002 -e TARGET_HOST=host.docker.internal apache/spark-connect-swift:stream
+
+# From source code
+swift run
+```
+
+Type text into the Netcat terminal to see real-time word counting from `Spark Connect Server` container.
+
+## Web Application Example
+
+The web application example showcases how to integrate Spark Connect Swift with a web server using the Vapor framework.
+
+### Key Features
+- HTTP server integration with Vapor
+- REST API endpoints
+- Spark session management within web requests
+- Version information retrieval
+
+### How to Run
+
+Build and run the application:
+
+```bash
+# Using Docker
+docker build -t apache/spark-connect-swift:web .
+docker run -it --rm -p 8080:8080 -e SPARK_REMOTE=sc://host.docker.internal:15002 apache/spark-connect-swift:web
+
+# From source code
+swift run
+```
+
+Access the web application:
+
+```bash
+# Root endpoint
+$ curl http://127.0.0.1:8080/
+Welcome to the Swift world. Say hello!%
+
+# Spark-powered endpoint
+curl http://127.0.0.1:8080/hello
+Hi, this is powered by the Apache Spark 4.0.0-preview2.%
+```
+
+## Development Environment
+
+All examples include:
+- A Dockerfile for containerized execution
+- A Package.swift file for Swift Package Manager configuration
+- A README.md with detailed instructions
+- Source code in the Sources directory
+
+These examples are designed to be used with Apache Spark 4.0.0 or newer, using the Spark Connect protocol for client-server interaction.