Add GitHub Actions workflow for deploying to GitHub Pages and update README with deployment instructions

Author: chijure

.github/workflows/deploy.yml

@@ -0,0 +1,51 @@
+name: Deploy to GitHub Pages
+
+on: 
+  push:
+    branches: 
+      - master
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+          
+      - name:  Install dependencies
+        run: npm ci
+        
+      - name: Build
+        run: npm run build
+        
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./dist
+
+  deploy:
+    environment: 
+      name: github-pages
+      url: ${{ steps.deployment. outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps: 
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

README.md

@@ -23,6 +23,13 @@ npm run build
 ```
 El resultado queda en `dist/`.
 
+## GitHub Pages
+- Ajusta `base` en `vite.config.ts` si el nombre del repo cambia (por defecto `/bbcode-preview/`).
+- Pages usa GitHub Actions (`.github/workflows/deploy.yml`):
+  - `npm ci` + `npm run build` con Node 18, caché npm.
+  - `actions/configure-pages`, `upload-pages-artifact`, `deploy-pages`.
+- Fuente de Pages: habilita GitHub Pages -> Build and deployment -> Source: GitHub Actions.
+
 ## Funcionalidad
 - Código en TypeScript.
 - Editor de BBCode con chips para insertar etiquetas rápidas.