Project Euler problems (numbering) : follow naming convention.

Author: lvlte

Project-Euler/Problem2.js renamed to Project-Euler/Problem002.js

@@ -1,4 +1,4 @@
-import { largestAdjacentNumber } from '../Problem8'
+import { largestAdjacentNumber } from '../Problem008'
 
 const grid1 = `73167176531330624919225119674426574742355349194934
 96983520312774506326239578318016984801869478851843

Project-Euler/Problem3.js renamed to Project-Euler/Problem003.js

@@ -1,4 +1,4 @@
-import { calculateSumOfPrimeNumbers } from '../Problem10'
+import { calculateSumOfPrimeNumbers } from '../Problem010'
 
 describe('checkAnagram', () => {
   it('Return the sum of prime numbers upto but less than 14', () => {