docs(docs): add Maximum Subarray problem page and redirect entry

apps/docs/redirects.ts

@@ -15,6 +15,7 @@ export default [
   { from: "/46", to: "/backtracking/permutations" },
   { from: "/48", to: "/matrix-index-math/rotate-image" },
   { from: "/49", to: "/hash-table/group-anagrams" },
+  { from: "/53", to: "/greedy/maximum-subarray" },
   { from: "/54", to: "/matrix-index-math/spiral-matrix" },
   { from: "/62", to: "/multi-d-grid-dp/unique-paths" },
   { from: "/64", to: "/multi-d-grid-dp/minimum-path-sum" },