docs: improve Quick Start commands layout for better copy-paste experience

Author: arcangelo7

README.md

@@ -29,13 +29,19 @@ Optionally download database management scripts for quick setup:
 **For Unix/Linux/macOS:**
 ```bash
 curl -o start-databases.sh https://raw.githubusercontent.com/opencitations/heritrace/main/start-databases.sh
+```
+```bash
 curl -o stop-databases.sh https://raw.githubusercontent.com/opencitations/heritrace/main/stop-databases.sh
+```
+```bash
 chmod +x start-databases.sh stop-databases.sh
 ```
 
 **For Windows:**
 ```bash
 curl -o Start-Databases.ps1 https://raw.githubusercontent.com/opencitations/heritrace/main/Start-Databases.ps1
+```
+```bash
 curl -o Stop-Databases.ps1 https://raw.githubusercontent.com/opencitations/heritrace/main/Stop-Databases.ps1
 ```