docs(docs): add page icon frontmatter to problem pages

apps/docs/content/(02-nodal-grid)/hybrid-structures/146-lru-cache.mdx

@@ -1,6 +1,7 @@
 ---
 title: '146. LRU Cache'
 description: Design a data structure that follows the constraints of a Least Recently Used (LRU) cache
+icon: line-dot-left-horizontal
 sidebar:
   label: 'LRU Cache'
   badge: 'Medium'

apps/docs/content/(02-nodal-grid)/hybrid-structures/2-add-two-numbers.mdx

@@ -1,6 +1,7 @@
 ---
 title: '2. Add Two Numbers'
 description: You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Add Two Numbers'
   badge: 'Medium'

apps/docs/content/(02-nodal-grid)/linked-list/141-linked-list-cycle.mdx

@@ -1,6 +1,7 @@
 ---
 title: '141. Linked List Cycle'
 description: Given head, the head of a linked list, determine if the linked list has a cycle in it
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Linked List Cycle'
   badge: 'Easy'

apps/docs/content/(02-nodal-grid)/linked-list/206-reverse-linked-list.mdx

@@ -1,6 +1,7 @@
 ---
 title: '206. Reverse Linked List'
 description: Given the head of a singly linked list, reverse the list, and return the reversed list
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Reverse Linked List'
   badge: 'Easy'

apps/docs/content/(02-nodal-grid)/linked-list/21-merge-two-sorted-lists.mdx

@@ -1,6 +1,7 @@
 ---
 title: '21. Merge Two Sorted Lists'
 description: You are given the heads of two sorted linked lists list1 and list2
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Merge Two Sorted Lists'
   badge: 'Easy'

apps/docs/content/(02-nodal-grid)/matrix-index-math/48-rotate-image.mdx

@@ -1,6 +1,7 @@
 ---
 title: '48. Rotate Image'
 description: You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise)
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Rotate Image'
   badge: 'Medium'

apps/docs/content/(02-nodal-grid)/matrix-index-math/54-spiral-matrix.mdx

@@ -1,6 +1,7 @@
 ---
 title: '54. Spiral Matrix'
 description: Given an m x n matrix, return all elements of the matrix in spiral order
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Spiral Matrix'
   badge: 'Medium'

apps/docs/content/(02-nodal-grid)/matrix-index-math/73-set-matrix-zeroes.mdx

@@ -1,6 +1,7 @@
 ---
 title: '73. Set Matrix Zeroes'
 description: Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's
+icon: line-dot-left-horizontal
 sidebar:
   label: 'Set Matrix Zeroes'
   badge: 'Medium'