fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/longest-streak/index.d.ts

@@ -0,0 +1,11 @@
+/**
+ * Get the count of the longest repeating streak of `substring` in `value`.
+ *
+ * @param {string} value
+ *   Content to search in.
+ * @param {string} substring
+ *   Substring to look for, typically one character.
+ * @returns {number}
+ *   Count of most frequent adjacent `substring`s in `value`.
+ */
+export function longestStreak(value: string, substring: string): number