Add horizontal lines as section separators and remove redundant CSS

This commit introduces horizontal line (<hr>) elements in the HTML to visually separate different sections. It also removes the 'overscroll-behavior-y' property and the unused '#projects.active' rule from the CSS file, thus streamlining the style sheet.

index.html

@@ -42,6 +42,7 @@
             </div>
         </article>
     </section>
+    <hr>
     <section id="projects">
         <h2>Projects</h2>
         <div class="project-scroller">
@@ -214,6 +215,7 @@
             </article>
         </div>
     </section>
+    <hr>
     <section id="socials">
         <h2>Socials</h2>
         <article>