Add initial project structure with Docker support and chapter downloading functionality

- Created .dockerignore and .gitignore files to exclude unnecessary files from Docker builds.
- Added Dockerfile for multi-stage build setup, including dependencies and production environment configuration.
- Introduced docker-compose.yml for service orchestration, including FlareSolverr and the main application.
- Implemented core functionality for downloading manga chapters, including utilities for handling file paths and chapter metadata.
- Added ESLint configuration for code quality and consistency.
- Included JSDoc configuration for documentation generation.
- Established initial package.json and package-lock.json with necessary dependencies for the project.

src/index.js

@@ -0,0 +1,19 @@
+const axios = require("axios");
+const { parse } = require("node-html-parser");
+
+/**
+ * Fetches HTML from a URL and returns the parsed document root.
+ * @async
+ * @param {string} url - Absolute URL to fetch.
+ * @returns {Promise<object>} Parsed HTML root (node-html-parser tree).
+ */
+async function fetchAndParseHtml(url) {
+  const { data } = await axios.get(url, {
+    responseType: "text",
+    validateStatus: (status) => status >= 200 && status < 300,
+    timeout: 15_000,
+  });
+  return parse(data);
+}
+
+module.exports = { fetchAndParseHtml };