Download fonts locally on build

Use rollup-plugin-bundle-fonts [1] to download fonts locally on build and
not rely on a CDN on production.

[1] https://github.com/mgreminger/rollup-plugin-bundle-fonts

Fixes #58 while carbon-design-system/carbon-components-svelte#1629 is
not finished.

.gitignore

@@ -1,6 +1,7 @@
 # App files
 /node_modules/
 /public/app/
+/public/fonts/
 config.json
 .env
 

package.json

@@ -22,6 +22,7 @@
     "eslint": "^8.0.0",
     "eslint-plugin-svelte3": "^4.0.0",
     "rollup": "^3.29.4",
+    "rollup-plugin-bundle-fonts": "^1.0.0",
     "rollup-plugin-css-only": "^4.5.2",
     "rollup-plugin-livereload": "^2.0.0",
     "rollup-plugin-svelte": "^7.0.0",

rollup.config.mjs

@@ -8,6 +8,7 @@ import typescript from '@rollup/plugin-typescript';
 import json from '@rollup/plugin-json';
 import css from 'rollup-plugin-css-only';
 import { copy } from '@web/rollup-plugin-copy';
+import bundleFonts from 'rollup-plugin-bundle-fonts';
 import sveltePreprocess from 'svelte-preprocess';
 import { optimizeCarbonImports as carbon } from "carbon-preprocess-svelte";
 import { execSync } from 'child_process';
@@ -64,6 +65,12 @@ export default {
 		// JSON plugin to convert translation files to modules.
 		json({ namedExports: false }),
 
+		// Download and package fonts localy
+		bundleFonts({
+			fontTargetDir: 'public/fonts',
+			cssBundleDir: 'public/app',
+		}),
+
 		// we'll extract any component CSS out into
 		// a separate file - better for performance
 		css({ output: 'bundle.css' }),