add 2 placeholder images for homepage hero

Author: outofambit

src/content/homepage/en.yaml

@@ -3,6 +3,12 @@ heroImages:
   - image: ./images/hero.webp
     altText: Lauren Lee McCarthy reading the Processing Community Catalog
     caption: "Lauren Lee McCarthy reading the Processing Community Catalog. Photo: Maximo Xtravaganza"
+  - image: ./images/salon-9.webp
+    altText: Image alt text here
+    caption: "New web editor features"
+  - image: ./images/2015-7.webp
+    altText: Image alt text here
+    caption: "Contributors Conference 2015"
 heroText: >
   p5.js is a friendly tool for learning to code and make art. It is a free and open-source JavaScript library built by an inclusive, nurturing community. p5.js welcomes artists, designers, beginners, educators, and anyone else!
 referenceHeaderText: Explore the p5.js library reference