Change name for banner script

Align with informal naming convention.

Author: Tim Bannister

assets/js/dismiss_banner.js renamed to assets/js/banner-dismiss.js

@@ -55,9 +55,9 @@
 
 {{/* JavaScript for announcements */}}
 {{- if hugo.IsProduction -}}
-  {{- $bannerDismissJs :=  resources.Get "js/dismiss_banner.js" | minify | fingerprint -}}
+  {{- $bannerDismissJs :=  resources.Get "js/banner-dismiss.js" | minify | fingerprint -}}
 <script defer src="{{ $bannerDismissJs.RelPermalink }}" integrity="{{ $bannerDismissJs.Data.Integrity }}" crossorigin="anonymous"></script>
 {{- else -}}
-  {{- $bannerDismissJs := resources.Get "js/dismiss_banner.js" -}}
+  {{- $bannerDismissJs := resources.Get "js/banner-dismiss.js" -}}
 <script defer src="{{ $bannerDismissJs.RelPermalink }}"></script>
 {{- end -}}