docs(welcome): restructure documentation directories and add new guides section

docs/(welcome)/array/1636.mdx

@@ -0,0 +1,46 @@
+---
+title: LC-1636
+description: Sort Array by Increasing Frequency
+---
+
+## Examples
+
+| Input                  | Output                 |
+| ---------------------- | ---------------------- |
+| `[1,1,2,2,2,3]`        | `[3,1,1,2,2,2]`        |
+| `[2,3,1,3,2]`          | `[1,3,3,2,2]`          |
+| `[-1,1,-6,4,5,-6,1,4,1]` | `[5,-1,4,4,-6,-6,1,1,1]` |
+
+## Hints
+
+<Accordion type="single">
+  <AccordionItem title="Constraints">
+    Constraints:
+     • `1 <= nums.length <= 100`
+     • `-100 <= nums[i] <= 100`
+  </AccordionItem>
+  <AccordionItem title="Problem Statement">
+    Given an array of integers nums, sort the array in increasing order based on the frequency of the values.
+    If multiple values have the same frequency, sort them in decreasing order.
+    Return the sorted array.
+  </AccordionItem>
+</Accordion>
+
+## Solution
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+
+var frequencySort = function (nums) {
+  // Default for Hammer
+  const freq = {};
+  for (let n of nums) freq[n] = (freq[n] || 0) + 1;
+
+  // Problem Specific
+  // Sort ascending by frequency; ties break by larger value first
+  return nums.sort((a, b) => freq[a] - freq[b] || b - a);
+};
+```