feat: 404 page

fix: linting errors
Signed-off-by: royalpinto007 <[email protected]>

404.html

@@ -0,0 +1,16 @@
+---
+layout: default
+title: 404
+permalink: /404
+nav_exclude: true
+search_exclude: true
+---
+
+<h1>Page not found</h1>
+
+<p>
+  The page you requested could not be found. Try using the navigation {% if
+  site.search_enabled != false %}or search {% endif %}to find what you're
+  looking for or go to this
+  <a href="{{ '/' | relative_url }}">site's home page</a>.
+</p>