Add Makefile, package.json, and initial configuration for VitePress and Slidev integration

- Introduced a Makefile for streamlined commands related to building, running, and managing presentations.
- Created package.json to define project metadata, dependencies, and scripts for development and testing.
- Added .gitignore entries to exclude build artifacts and temporary files from version control.
- Included playwright.config.mjs for end-to-end testing setup with Playwright.
- Added README.md for project documentation, outlining setup instructions and development guidelines.

tools/build-all-decks.mjs

@@ -0,0 +1,23 @@
+#!/usr/bin/env node
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { execFileSync } from 'node:child_process'
+import { listPresentationSlugs } from './list-slugs.mjs'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const root = path.resolve(__dirname, '..')
+
+const slugs = listPresentationSlugs(root)
+if (!slugs.length) {
+  console.log('[build-all-decks] aucune présentation')
+  process.exit(0)
+}
+
+for (const slug of slugs) {
+  execFileSync(process.execPath, [path.join(root, 'tools', 'build-deck.mjs'), slug], {
+    stdio: 'inherit',
+    cwd: root,
+    env: process.env,
+  })
+}
+console.log('[build-all-decks] terminé')