docs: replace legacy line‑dot‑left‑horizontal icons with unified dot icon across docs

apps/docs/content/(03-hierarchical)/trie/208-implement-trie-prefix-tree.mdx

@@ -1,7 +1,7 @@
 ---
 title: '208. Implement Trie (Prefix Tree)'
 description: A trie (pronounced as "try") or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker
-icon: line-dot-left-horizontal
+icon: dot
 sidebar:
   label: 'Implement Trie (Prefix Tree)'
   badge: 'Medium'