Add homepage announcement

Author: NeuroShepherd

_quarto.yml

@@ -13,6 +13,13 @@ website:
   repo-url: https://github.com/lmu-osc/lmu-osc.github.io
   repo-actions: [edit, issue]
 
+  announcement: 
+    icon: info-circle
+    dismissable: true
+    content: "**Thanks for visiting the LMU Open Science Center--our site is still under construction for now, but we'll be live soon!**"
+    type: primary
+    position: below-navbar
+
   navbar:
     title: false
     background: "#2b864b"