Added enemies to each dangerous tile in main map.

Comments for Diana:

So, currently, I'm loading the enemies by iterating through the entire
currentMap that's assigned during loadContent -- therefore, it will not
load any enemies in other maps ATM.

If you walk across a dangerous tile, the console will output the names
of enemies that are in all the lists for your reference.

Here's the enemy properties:
Texture2D - enemyTexture
String - enemyName
int - HP
int - enemySpeed
int - Damage
int - Experience
int - money
List<Item> - EnemyItemsList