Fix: all headers

Author: lwasser

_posts/2024-06-03-sleplet-slepian-wavelets.md

@@ -5,8 +5,7 @@ excerpt: SLEPLET is a tool to create Slepian scale-discretised wavelets that has
 author: Patrick J. Roddy
 permalink: /blog/sleplet-slepian-wavelets
 header:
-    overlay_image: /images/sleplet/planck_2018_temp_mask.jpg
-    overlay_filter: rgba(20, 13, 36, 0.8)
+    overlay_image: images/blog/headers/sleptlet-header.png
     caption: "Figure credit: [**The Planck Collaboration 2018**](https://www.aanda.org/articles/aa/full_html/2020/09/aa33881-18/F38.html)"
 categories:
   - blog-post

_posts/2024-07-10-automata.md

@@ -5,8 +5,7 @@ excerpt: automata is a package implementing structures and algorithms for manipu
 author: Eliot W. Robson
 permalink: /blog/automata
 header:
-    overlay_image: /images/automata/finite_language_dfa.png
-    overlay_filter: rgba(20, 13, 36, 0.8)
+    overlay_image: /images/blog/headers/automata-header.png
 categories:
   - blog-post
   - automata

_posts/2025-01-17-quadratik.md

@@ -6,7 +6,6 @@ author: "Raktim Mukhopadhyay"
 permalink: /blog/quadratik.html
 header:
   overlay_image: images/headers/pyopensci-quadratik.png
-  overlay_filter: rgba(20, 13, 36, 0.7)
 categories:
   - blog-post
   - quadratic distances