♻️ Refactor: author's avatar of post or profile (#288)

1. `params.profile.gravatarEmail` only takes effect when `params.gravatar.enable=true`
2. Adjust frontmatter: `author` data type from string to **map**
3. Remove frontmatter: `gravatarForce`, `authorLink`, `authorEmail`
4. Add frontmatter: `authorAvatar`
5. Add `params.gravatar.enable`

archetypes/posts.md

@@ -3,9 +3,11 @@ title: "{{ replace .TranslationBaseName "-" " " | title }}"
 subtitle: ""
 date: {{ .Date }}
 draft: true
-author: ""
-authorLink: ""
-authorEmail: ""
+author:
+  name: ""
+  link: ""
+  email: ""
+  avatar: ""
 description: ""
 keywords: ""
 license: ""