Rename config.yml to hugo.yml (#38582)

hugo.yml is now recommended (over the generic sounding config.yml) as the default config based filename
REF: https://gohugo.io/getting-started/configuration/#hugotoml-vs-configtoml
Changing this may make it easier for code editors and build tools to identify this as a Hugo configuration file and project.

build/generate-sri.js

@@ -18,11 +18,11 @@ const sh = require('shelljs')
 
 sh.config.fatal = true
 
-const configFile = path.join(__dirname, '../config.yml')
+const configFile = path.join(__dirname, '../hugo.yml')
 
 // Array of objects which holds the files to generate SRI hashes for.
 // `file` is the path from the root folder
-// `configPropertyName` is the config.yml variable's name of the file
+// `configPropertyName` is the hugo.yml variable's name of the file
 const files = [
   {
     file: 'dist/css/bootstrap.min.css',