docs: add Spanish README, local docker-compose build and .env.example

- Rewrite README entirely in Spanish referencing paste.es / cloudhost.es
- Update docker-compose to build from local Dockerfile, use .env file,
  mount data/ volumes and respect PORT env var
- Add .env.example with full commented reference for all supported
  HEMMELIG_* variables (analytics disabled by default for privacy)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -1,19 +1,17 @@
 services:
-    hemmelig:
-        image: hemmeligapp/hemmelig:v7
-        container_name: hemmelig
+    paste-es:
+        build:
+            context: .
+            dockerfile: Dockerfile
+        container_name: paste-es
         restart: unless-stopped
+        env_file:
+            - .env
         volumes:
-            - ./database:/app/database
-            - ./uploads:/app/uploads
-        environment:
-            - DATABASE_URL=file:/app/database/hemmelig.db
-            - BETTER_AUTH_SECRET=change-this-to-a-secure-secret-min-32-chars
-            - BETTER_AUTH_URL=https://secrets.example.com
-            - NODE_ENV=production
-            - HEMMELIG_BASE_URL=https://secrets.example.com
+            - ./data/database:/app/database
+            - ./data/uploads:/app/uploads
         ports:
-            - '3000:3000'
+            - '${PORT:-3000}:3000'
         healthcheck:
             test:
                 [
@@ -27,4 +25,4 @@ services:
             interval: 30s
             timeout: 10s
             retries: 3
-            start_period: 10s
+            start_period: 15s