gh-36066: Fix link to tutorial in PDF docs. This fixes #35736.
    
Fix link to PDF tutorial (English) in docs. This should fix #35736.

<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes #1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

The document name for the English tutorial is broken: it doesn't match
the name expected in the index.html file for the documentation. So we
change the document name.

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [X] The title is concise, informative, and self-explanatory.
- [X] The description explains in detail what this PR is about.
- [X] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36066
Reported by: John H. Palmieri
Reviewer(s): Kwankyu Lee

Author: Release Manager

src/doc/en/website/root_index.html

@@ -113,7 +113,7 @@ <h1>Sage Documentation</h1>
 <div class="cell lang"><a href='html/en/index.html'>English</a></div>
 <div class="cell doc">
 <div class='entry lang-en'><a href='pdf/en/a_tour_of_sage/a_tour_of_sage.pdf'>A Tour of Sage</a></div>
-<div class='entry lang-en'><a href='pdf/en/tutorial/SageTutorial.pdf'>Tutorial</a></div>
+<div class='entry lang-en'><a href='pdf/en/tutorial/sage_tutorial.pdf'>Tutorial</a></div>
 <div class='entry lang-en'><a href='pdf/en/thematic_tutorials/thematic_tutorials.pdf'>Thematic Tutorials</a></div>
 <div class='entry lang-en'><a href='pdf/en/prep/prep_tutorials.pdf'>PREP Tutorials</a></div>
 <div class='entry lang-en'><a href='pdf/en/constructions/constructions.pdf'>Constructions</a></div>