Implement LSP Example VSCode Client Extension

[hankhsu1996]

Overview

This PR introduces a basic "Hello World" example of a VSCode client extension that interfaces with an existing LSP server. The LSP server handles essential LSP methods, including initialize and textDocument/completion.

Changes

• Client Implementation:
  • Implemented extension.ts to set up the VSCode client using vscode-languageclient.
  • Configured the client to use TransportKind.pipe for communication with the LSP server.
  • Added an output channel to monitor LSP and JSON-RPC messages for debugging and visibility.

Functionality

• Typing "hello " in a plaintext file triggers the LSP server to suggest "world" as a completion.
• The output channel logs LSP and JSON-RPC messages, allowing observation of client-server interactions.

Purpose

This example demonstrates a simple yet effective integration of a VSCode client with a custom LSP server, providing foundational insight into LSP functionality and client-server communication.