add image to linear convection post

Author: timothypratley

src/scicloj/cfd/intro/linear.png

@@ -3,6 +3,7 @@
   {:title  "Simulating 1-D Convection in Clojure — From Equations to Arrays"
    :quarto {:author      :syungb
             :description "A quick exploration to simulate a classic fluid dynamics equation in Clojure using Java arrays."
+            :image       "linear.png"
             :type        :post
             :date        "2025-07-15"
             :category    :clojure
@@ -173,4 +174,4 @@
 
 (comment
   (require '[scicloj.clay.v2.api :as clay])
-  (clay/make! {:source-path "scicloj/cfd/intro/linear_1d_convection_with_array.clj"}))
+  (clay/make! {:source-path "scicloj/cfd/intro/linear_1d_convection_with_array.clj"}))