refactor: prefine for version v1.0.2 (#269)

* refactor: refactor navigateVector logic and remove unused functions

* refactor: refactor HTML structure and styling in single.html

- Modify the `.info` class to `article` in `_article.scss`
- Remove the `nav.html` partial in `single.html`
- Change the class name from `info` to `article` in `single.html`
- Add the `nav.html` partial in `single.html`

* refactor: update handling of 404 page
- Now hugo will set unknown page title as "404"
- Add condition to return an empty image array if the document title starts with "404"

* docs: update documentation

assets/scss/_partial/_article.scss

@@ -1,4 +1,4 @@
-.info {
+article {
   padding: var(--space-standard);
   max-width: 25em;
 
@@ -42,7 +42,7 @@
 }
 
 @media (max-width: $tablet), (hover: none) {
-  .info {
+  article {
     margin-top: var(--nav-height);
   }
 }