chore: Add all calculus based topics to one point (#34398)

guide/english/mathematics/calculus/index.md

@@ -1,15 +1,10 @@
 ---
-title: Partial Derivatives Introduction
+title: Calculus
 ---
-## Partial Derivatives Introduction
-
-This is a stub. <a href='https://github.com/freecodecamp/guides/tree/master/src/pages/mathematics/partial-derivatives-introduction/index.md' target='_blank' rel='nofollow'>Help our community expand it</a>.
+## Calculus
 
+This is a stub. <a href='https://github.com/freecodecamp/guide/tree/master/src/pages/mathematics/calculus/index.md' target='_blank' rel='nofollow'>Help our community expand it</a>.
 <a href='https://github.com/freecodecamp/guides/blob/master/README.md' target='_blank' rel='nofollow'>This quick style guide will help ensure your pull request gets accepted</a>.
-
 <!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
-
 #### More Information:
-<!-- Please add any articles you think might be helpful to read before writing the article -->
-
-
+<!-- Please add any articles you think might be helpful to read before writing the article -->