Rename the Java files starting with a. (#145)

* Rename arithmetic-subarrays.java to Arithmetic-Subarrays.java

* Update README.md

Update Arithmetic-Subarrays.java

* Rename armstrong-number.java to Armstrong-Number.java

* Update README.md

Update Armstrong-Number.java

* Update README.md

Update Add-Two-Numbers

Author: JeongDaHyeon

Java/arithmetic-subarrays.java renamed to Java/Arithmetic-Subarrays.java

@@ -66,4 +66,4 @@ public List<Boolean> checkArithmeticSubarrays(int[] nums, int[] l, int[] r) {
 
         return res;
     }
-}
+}

Java/armstrong-number.java renamed to Java/Armstrong-Number.java

@@ -121,7 +121,7 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | 1480    | [Running Sum of 1d Array](https://leetcode.com/problems/running-sum-of-1d-array/)                                             | [Java](./Java/running-sum-of-1d-array.java)                                                                       | _O(N)_       | _O(N)_        | Easy       | Simple sum         |                                          |
 | 42      | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/)                                                     | [Python](./Python/trapping_rain.py)                                                                               | _O(N^2)_     | _O(N)_        | Hard       | Array              |                                          |
 | 11      | [Container with Most Water](https://leetcode.com/problems/container-with-most-water/)                                         | [Python](./Python/container_with_most_water.py)                                                                   | _O(N)_       | _O(N)_        | Medium     | Array Two Pointers |                                          |
-| 1134 🔒 | [Armstrong Number](https://leetcode.com/problems/armstrong-number/)                                                           | [Java](./Java/armstrong-number.java)                                                                              | _O(N)_       | _O(1)_        | Easy       |                    |                                          |
+| 1134 🔒 | [Armstrong Number](https://leetcode.com/problems/armstrong-number/)                                                           | [Java](./Java/Armstrong-Number.java)                                                                              | _O(N)_       | _O(1)_        | Easy       |                    |                                          |
 | 1534    | [Count Good Triplets](https://leetcode.com/problems/count-good-triplets/)                                                     | [Python](./Python/count-good-triplets.py)                                                                         | _O(N^3)_     | _O(1)_        | Easy       |                    |                                          |
 | 1572    | [Matrix Diagonal Sum](https://leetcode.com/problems/matrix-diagonal-sum/)                                                     | [Java](./Java/matrix-diagonal-sum.java)                                                                           | _O(N)_       | _O(1)_        | Easy       |                    |                                          |
 | 811     | [Subdomain Visit Count](https://leetcode.com/problems/subdomain-visit-count/)                                                 | [Javascript](./JavaScript/Subdomain-Visit-Count.js)                                                               | _O(N\*M)_    | _O(N\*M + N)_ | Easy       |                    |                                          |
@@ -170,7 +170,7 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 
 | #   | Title                                                                                                                 | Solution                                                                            | Time       | Space  | Difficulty | Tag                | Note |
 | --- | --------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ---------- | ------ | ---------- | ------------------ | ---- |
-| 002 | [Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)                                                     | [Java](./Java/add-two-numbers.java)                                                 | _O(n)_     | _O(n)_ | Medium     | Math               |      |
+| 002 | [Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)                                                     | [Java](./Java/Add-Two-Numbers.java)                                                 | _O(n)_     | _O(n)_ | Medium     | Math               |      |
 | 19  | [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)                   | [Java](./Java/remove-nth-node-from-end-of-list.java)                                | _O(n)_     | _O(1)_ | Medium     | Two pointers       |      |
 | 23  | [Merge K sorted lists](https://leetcode.com/problems/merge-k-sorted-lists/)                                           | [C++](./C++/merge-k-sorted-lists.cpp)                                               | _O(nlogn)_ | _O(n)_ | Hard       | sorting and append |      |
 | 109 | [Convert Sorted List to Binary Search Tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/) | [Java](./Java/convert-sorted-list-to-binary-search-tree.java)                       | _O(n)_     | _O(n)_ | Medium     | LinkedList         |      |
@@ -297,7 +297,7 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | 326 | [Power of Three](https://leetcode.com/problems/power-of-three)                        | [Java](./Java/Power-of-Three.java)                                         | _O(logn)_         | _O(n)_ | Easy       | Math   |      |
 | 12  | [Integer to Roman](https://leetcode.com/problems/integer-to-roman)                    | [Java](./Java/integer-to-roman.java)                                       | _O(n)_            | _O(1)_ | Medium     | Math   |      |
 | 13  | [Roman to Integer](https://leetcode.com/problems/roman-to-integer)                    | [Java](./Java/roman-to-integer.java)                                       | _O(n)_            | _O(1)_ | Easy       | Math   |      |
-| 14  | [Arithmetic Subarrays](https://leetcode.com/problems/arithmetic-subarrays/)                    | [Java](./Java/arithmetic-subarrays.java)                                       | _O(m*n)_            | _O(n)_ | Medium       | Math   | Pattern Count  |
+| 14  | [Arithmetic Subarrays](https://leetcode.com/problems/arithmetic-subarrays/)                    | [Java](./Java/Arithmetic-Subarrays.java)                                       | _O(m*n)_            | _O(n)_ | Medium       | Math   | Pattern Count  |
 
 <br/>
 <div align="right">