Do not statically serve the index template prior to rendering it

Without this, going to `https://thelounge.example.com/index.html` would return the raw file. This now excludes it from the `public` folder so it cannot be rendered as is.
Renaming the file is for good measure, to indicate that this HTML file must be templated. Because it is a straight rename with no modification, rebasing PRs on it should not be to painful, as git re-applies changes on renamed files.

.npmignore

@@ -11,6 +11,7 @@
 client/**
 !client/js/libs/handlebars/ircmessageparser/findLinks.js
 !client/js/libs/handlebars/ircmessageparser/cleanIrcMessage.js
+!client/index.html.tpl
 
 public/js/bundle.vendor.js.map
 coverage/

src/server.js

@@ -251,7 +251,7 @@ function index(req, res, next) {
 	res.setHeader("Content-Security-Policy", policies.join("; "));
 	res.setHeader("Referrer-Policy", "no-referrer");
 
-	return fs.readFile(path.join(__dirname, "..", "public", "index.html"), "utf-8", (err, file) => {
+	return fs.readFile(path.join(__dirname, "..", "client", "index.html.tpl"), "utf-8", (err, file) => {
 		if (err) {
 			throw err;
 		}

test/tests/build.js

@@ -12,8 +12,9 @@ describe("public folder", function() {
 		expect(fs.existsSync(path.join(publicFolder, "fonts", "fontawesome-webfont.woff2"))).to.be.true;
 	});
 
-	it("index.html is copied", function() {
-		expect(fs.existsSync(path.join(publicFolder, "index.html"))).to.be.true;
+	it("index HTML file is not copied", function() {
+		expect(fs.existsSync(path.join(publicFolder, "index.html"))).to.be.false;
+		expect(fs.existsSync(path.join(publicFolder, "index.html.tpl"))).to.be.false;
 	});
 
 	it("javascript files are built", function() {

webpack.config.js

@@ -70,9 +70,10 @@ const config = {
 				from: "./client/js/loading-error-handlers.js",
 				to: "js/[name].[ext]",
 			},
-			{ // TODO: Build index.html with handlebars
+			{
 				from: "./client/*",
 				to: "[name].[ext]",
+				ignore: "index.html.tpl",
 			},
 			{
 				from: "./client/audio/*",