docs(content): add issue URLs to problem pages and restructure guides into appendix

apps/docs/content/(05-decision-space)/1d-dynamic-programming/198-house-robber.mdx

@@ -5,6 +5,7 @@ icon: dot
 topics:
   - { name: "Array", slug: "array" }
   - { name: "Dynamic Programming", slug: "dynamic-programming" }
+issue: "https://github.com/prdlk/leetcode/issues/158"
 sidebar:
   label: 'House Robber'
   badge: 'Medium'

apps/docs/content/(05-decision-space)/1d-dynamic-programming/322-coin-change.mdx

@@ -8,6 +8,7 @@ topics:
   - { name: "Breadth-First Search", slug: "breadth-first-search" }
   - { name: "Knapsack Problem", slug: "knapsack-problem" }
   - { name: "Complete Knapsack", slug: "complete-knapsack" }
+issue: "https://github.com/prdlk/leetcode/issues/159"
 sidebar:
   label: 'Coin Change'
   badge: 'Medium'

apps/docs/content/(05-decision-space)/1d-dynamic-programming/70-climbing-stairs.mdx

@@ -6,6 +6,7 @@ topics:
   - { name: "Math", slug: "math" }
   - { name: "Dynamic Programming", slug: "dynamic-programming" }
   - { name: "Memoization", slug: "memoization" }
+issue: "https://github.com/prdlk/leetcode/issues/157"
 sidebar:
   label: 'Climbing Stairs'
   badge: 'Easy'