add PDE header to navbar

_build/pdes/elliptic.html

@@ -9,7 +9,7 @@
 prev_page:
   url: /pdes/partial-differential-equations.html
 next_page:
-  url: /quizzes/quiz2-IVPs.html
+  url: /pdes/parabolic.html
 suffix: .ipynb
 search: u j equation x begin end partial y points boundary n frac where k bmatrix using grid point delta mathbf vdots heat solve values b method example align solution laplaces right figure center us value index formula transfer text xi d square recursion well quad row old problems left temperature style lets conditions dimensional column jacobi nabla equations img src images png alt width px figcaptionfigure difference figcaption nine unknowns very matrix cdots elliptic pde step h vector mapping into columns m ghost iterative gauss seidel shows also finite differences central used direction five stencil consider td above system major
 

_data/toc.yml

@@ -50,6 +50,8 @@
   - url: /bvps/finite-difference
   - url: /bvps/eigenvalue
 
+- header: Partial Differential Equations
+
 - url: /pdes/partial-differential-equations
   expand_sections: true
   sections: