Fix link to be *true* raw data

Which would be handy for `wget`

Author: theidexisted

doc/source/getting_started/intro_tutorials/includes/titanic.rst

@@ -26,6 +26,6 @@ consists of the following data columns:
 .. raw:: html
 
             </p>
-            <a href="https://github.com/pandas-dev/pandas/tree/main/doc/data/titanic.csv" class="btn btn-dark btn-sm">To raw data</a>
+            <a href="https://github.com/pandas-dev/pandas/raw/main/doc/data/titanic.csv" class="btn btn-dark btn-sm">To raw data</a>
         </div>
     </div>