Feat/#21 restructure resources

[maakep]

Description

GitHub issue: #21 So I read up a little bit on Resources.Load and Unity seems to discourage the use of it for these reasons:

• Use of the Resources folder makes fine-grained memory management more difficult
• Improper use of Resources folders will increase application startup time and the length of builds
• As the number of Resources folders increases, management of the Assets within those folders becomes very difficult
• The Resources system degrades a project's ability to deliver custom content to specific platforms and eliminates the possibility of incremental content upgrades
• AssetBundle Variants are Unity's primary tool for adjusting content on a per-device basis

and good usages:

• Examples of this second case include MonoBehaviour singletons used to host prefabs

Which is what I've attempted here.

Source https://unity3d.com/learn/tutorials/topics/best-practices/resources-folder

How to test / set up

1. Load any scene
2. Verify that it has ManagerManager (and that ManagerManager is still connected to the prefab so it has gotten the new PrefabRepositry)
3. Verify that things still seem to work as intended

Code hygiene

• [ ] The code handles errors gracefully
• [x] The code doesn't contain unnecesary commented out code
• [x] The code doesn't contain spamming/forgotten/unclear Debug.Log()s
• [x] The code is properly formatted