Add analytics.openneo.net tags

Self-hosted Plausible instance! I have need of usage numbers again,
after a good few years of just not using it; but I don't want to send
the data to Google, and I enjoy self-hosting things, so here we have it!

app/views/layouts/application.html.haml

@@ -13,6 +13,7 @@
     %link{href: image_path('favicon.png'), rel: 'icon'}
     = yield :stylesheets
     = stylesheet_link_tag "application"
+    = render 'static/analytics'
     = yield :meta
     = open_graph_tags
     = csrf_meta_tag

app/views/outfits/edit.html.haml

@@ -17,6 +17,7 @@
     %link{href: image_path('favicon.png'), rel: 'icon'}
     = stylesheet_link_tag 'fonts'
     = javascript_include_tag 'wardrobe-2020-page', defer: true
+    = render 'static/analytics'
     = open_graph_tags
     = csrf_meta_tags
     %meta{name: 'dti-current-user-id', content: user_signed_in? ? current_user.id : "null"}

app/views/static/_analytics.html.erb

@@ -0,0 +1,2 @@
+<%= javascript_include_tag 'https://analytics.openneo.net/js/script.js',
+    defer: true, 'data-domain': 'impress.openneo.net' %>