refactor(config): use YAML instead of TOML

closes #62

exampleSite/config.yaml

@@ -0,0 +1,110 @@
+baseurl: 'https://example.com'
+languageCode: en-us
+theme: hugo-theme-stack
+paginate: 5
+title: Example Site
+disqusShortname: hugo-theme-stack           # Change it to your Disqus shortname before using
+DefaultContentLanguage: en                  # Theme i18n support
+
+permalinks:
+    post: '/p/:slug/'
+    page: '/:slug/'
+
+params:
+    mainSections:
+        - post
+    featuredImageField: image
+    rssFullContent: true
+
+    dateFormat:
+        published: Jan 02, 2006
+        lastUpdated: Jan 02, 2006 15:04 MST
+
+    sidebar:
+        emoji: 🍥
+        subtitle: Lorem ipsum dolor sit amet, consectetur adipiscing elit.
+        avatar:
+            local: true
+            src: img/avatar.png
+
+    article:
+        math: false
+        license:
+            enabled: true
+            default: Licensed under CC BY-NC-SA 4.0
+
+    comments:
+        enabled: true
+        provider: disqus
+        utterances:
+            repo: 
+            issueTerm: pathname
+            label: 
+            theme: preferred-color-scheme
+
+    widgets:
+        enabled:
+            - search
+            - archives
+            - tag-cloud
+
+        archives:
+            limit: 5
+            path: archives
+
+        tagCloud:
+            limit: 10
+
+    opengraph:
+        twitter:
+            site: 
+            card: summary_large_image
+
+    defaultImage:
+        opengraph:
+            enabled: false
+            local: false
+            src: 
+
+menu:
+    main:
+        -
+            identifier: home
+            name: Home
+            url: /
+            weight: -100
+            pre: home
+        -
+            identifier: about-cn
+            name: About
+            url: about
+            weight: -90
+            pre: user
+        -
+            identifier: archives
+            name: Archives
+            url: archives
+            weight: -70
+            pre: archives
+        -
+            identifier: search
+            name: Search
+            url: search
+            weight: -60
+            pre: search
+
+related:
+    includeNewer: true
+    threshold: 60
+    toLower: false
+    indices:
+        -
+            name: tags
+            weight: 100
+        -
+            name: categories
+            weight: 200
+
+markup:
+    highlight:
+        noClasses: false