* Adding topics to prime factors

* Adding math as problem area

* Removing recursion as a topic

Add topics to sieve

Add topics to problem 'nth-prime'

Added topics to Matrix exercise. Fixes #852

Added Topics to Collatz Conjecture #870

Added stubs to Matrix #547

complex-numbers: Add topics for exercise to config.json per #873

Add new exercise section to the contributing guide

Added stubs to LargestSeriesProductCalculator

Make changes per review comments

Made class and methods package private

* Completes #853

* Add more topics to problem Kindergarten-garden

* Correct the identation

* Correct the identation again

list-ops: add hint of using static methods per #378

wordy: add topics for exercise to config.json per #850

* added topics to perfect numbers

* updated topics

* fixed tabs

Add topics to sum of multiples exercise

Add topics to Secret Handshake exercise

Add topics to transpose exercise

scrabble-score: add topics

Removed recursion

Add topics to pascals-triangle

Triangle: Replace enum with isEquilateral, is Isosceles, and isScalene methods

Add topics to rna-transcription

Re-arrange to put "loops" before "maps".

added diamond topics

added topics to roman numerals

BST: add angle brackets when calling constructor