docs(en): order the section alphabetically (#1007)

docs/en/README.md

@@ -1,11 +1,17 @@
 # Algorithms
 
+## Backtracking
+- [N-Queens](./Backtracking/N-Queens.md)
+
 ## Lists
 - [Singly linked list](./Lists/singly-linked-list.md)
 - [Doubly linked list](./Lists/doubly-linked-list.md)
 
-## Sorting
+## Searching
+- [Binary Search](./Searching/Binary-Search.MD)
+- [Linear Search](./Searching/Linear-Search.md)
 
+## Sorting
 - [Bubble Sort](./Sorting/Bubble-Sort.md)
 - [Merge Sort](./Sorting/Merge-Sort.md)
 - [Selection Sort](./Sorting/Selection-Sort.md)
@@ -13,16 +19,13 @@
 - [Heap Sort](./Sorting/Heap-Sort.md)
 - [Quick Sort](./Sorting/Quick-Sort.md)
 - [Cycle Sort](./Sorting/Cycle-Sort.md)
+- [Radix Sort](./Sorting/Radix-Sort.md)
 
 ## Strings
-
 - [Palindrome](./Strings/Palindrome.md)
 
-## Searching
-
-- [Binary Search](./Searching/Binary-Search.MD)
-- [Linear Search](./Searching/Linear-Search.md)
+## Tree
+- [Min Heap](./Tree/min-heap.md)
 
 ## Others
-
 [How to add new algorithm documentation?](./CONTRIBUTING.md)