Configure builds

- Create `dartsass.builds` initializer and add all Sass files to be compiled. See https://github.com/rails/dartsass-rails#configuring-builds
- Create .keep
- Update manifest file to use /builds directory
- Ignore /builds

.gitignore

@@ -23,4 +23,8 @@ node_modules
 yarn-error.log
 
 # IntelliJ
-.idea/
+.idea/
+
+# Dart Sass
+/app/assets/builds/*
+!/app/assets/builds/.keep

app/assets/config/manifest.js

@@ -1,10 +1,5 @@
-//= link application.css
+//= link_tree ../builds
 
-//= link components/_result-card.css
-//= link components/_result-item.css
-//= link components/_result-sections.css
-
-//= link visualise.css
 //= link joint.css
 //= link application.js
 //= link dagre.js

config/initializers/dartsass.rb

@@ -0,0 +1,11 @@
+APP_STYLESHEETS = {
+  "application.scss" => "application.css",
+  "components/_result-card.scss" => "components/_result-card.css",
+  "components/_result-item.scss" => "components/_result-item.css",
+  "components/_result-sections.scss" => "components/_result-sections.css",
+  "visualise.scss" => "visualise.css",
+}.freeze
+
+all_stylesheets = APP_STYLESHEETS.merge(GovukPublishingComponents::Config.all_stylesheets)
+Rails.application.config.dartsass.builds = all_stylesheets
+Rails.application.config.dartsass.build_options << " --quiet-deps"