docs(guides): add icons and sidebar badges to guide pages

apps/docs/content/guides/(1-data-structures)/array.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Array"
 list: "https://leetcode.com/problem-list/array/"
+icon: list-ordered
+sidebar:
+  badge: '38'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/binary-tree.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Binary Tree"
 list: "https://leetcode.com/problem-list/binary-tree/"
+icon: git-branch
+sidebar:
+  badge: '9'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/directed-acyclic-graph.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Directed Acyclic Graph"
 list: "https://leetcode.com/problem-list/directed-acyclic-graph/"
+icon: route
+sidebar:
+  badge: '1'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/doubly-linked-list.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Doubly-Linked List"
 list: "https://leetcode.com/problem-list/doubly-linked-list/"
+icon: link-2
+sidebar:
+  badge: '1'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/graph.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Graph Theory"
 list: "https://leetcode.com/problem-list/graph/"
+icon: share-2
+sidebar:
+  badge: '5'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/k-d-tree.mdx

@@ -1,6 +1,9 @@
 ---
 title: "K-D Tree"
 list: "https://leetcode.com/problem-list/k-d-tree/"
+icon: axis-3d
+sidebar:
+  badge: '1'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/queue.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Queue"
 list: "https://leetcode.com/problem-list/queue/"
+icon: list-end
+sidebar:
+  badge: '1'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/string.mdx

@@ -1,6 +1,9 @@
 ---
 title: "String"
 list: "https://leetcode.com/problem-list/string/"
+icon: quote
+sidebar:
+  badge: '16'
 ---
 
 :::note

apps/docs/content/guides/(1-data-structures)/tree.mdx

@@ -1,6 +1,9 @@
 ---
 title: "Tree"
 list: "https://leetcode.com/problem-list/tree/"
+icon: tree-deciduous
+sidebar:
+  badge: '9'
 ---
 
 :::note