Add a script to generate documentation for config.js based on comments

scripts/generate-config-doc.js

@@ -0,0 +1,61 @@
+"use strict";
+
+// Usage: `node generate-config-doc.js DOC_REPO_PATH`
+//
+// Example:
+//
+// ```sh
+// node scripts/generate-config-doc.js ../thelounge.github.io/
+// ```
+
+const {readFileSync, writeFileSync} = require("fs");
+const colors = require("colors/safe");
+const log = require("../src/log");
+const {join} = require("path");
+const {spawnSync} = require("child_process");
+
+function getGitUsername() {
+	return spawnSync("git", ["config", "user.name"], {encoding: "utf8"})
+		.stdout
+		.trim();
+}
+
+const configContent = readFileSync(
+	join(__dirname, "..", "defaults", "config.js"),
+	"utf8"
+);
+
+const docPath = join(process.argv[2], "_includes", "config.js.md");
+
+const extractedDoc = configContent
+	.split("\n")
+	.reduce((acc, line) => {
+		line = line.trim();
+
+		if (line.startsWith("// ")) {
+			acc.push(line.substr(3));
+		} else if (acc.length > 0 && acc[acc.length - 1] !== "") {
+			// Treat whitespaces between comment blocks as separators in the generated
+			// Markdown. Multiple blank lines are treated as one.
+			acc.push("");
+		}
+
+		return acc;
+	}, []).join("\n");
+
+const infoBlock = `<!--
+DO NOT EDIT THIS FILE MANUALLY.
+Content for the following is generated by this script in the main repo:
+https://github.com/thelounge/lounge/blob/master/scripts/generate-config-doc.js
+Last updated at ${Date()} by ${getGitUsername()}
+-->`;
+
+const generatedContent = `${infoBlock}\n\n${extractedDoc}\n${infoBlock}\n`;
+
+writeFileSync(docPath, generatedContent);
+
+log.info(
+	`${colors.bold(generatedContent.split("\n").length)} lines ` +
+	`(${colors.bold(generatedContent.length)} characters) ` +
+	`were written in ${colors.green(docPath)}.`
+);