Update API documentation and configuration files

- Changed the base URL in the introduction documentation from `http://localhost:8000` to `https://finance.truncgil.com` for accurate API access.
- Updated the `.filehashes` to reflect changes in the `intro.md` file.
- Modified API endpoint responses to return a 404 status with a more user-friendly error message: "Data not found" instead of "Currency not found".
- Revised example values for `currencyName` and `goldName` in the API documentation to improve clarity and usability.
- Added a new Nginx configuration file to set up server parameters for the application.
- Adjusted file permissions for various `.gitignore` files to enhance security.

These changes improve the accuracy of the API documentation and enhance the overall user experience when interacting with the API.

nginx/default.conf

@@ -0,0 +1,24 @@
+server {
+    listen 80;
+ 
+    add_header Content-Security-Policy "upgrade-insecure-requests"; 
+    index index.php index.html;
+    server_name localhost;
+    root /var/www/public;
+
+    location / {
+        try_files $uri $uri/ /index.php?$query_string;
+    }
+
+    location ~ \.php$ {
+        proxy_set_header X-Forwarded-Proto $scheme;
+        include fastcgi_params;
+        fastcgi_pass app:9000;
+        fastcgi_index index.php;
+        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
+    }
+
+    location ~ /\.ht {
+        deny all;
+    }
+}