Bridger - Gameplay redesign

The game has been updated to be more player friendly and there has been a small expansion of the game. Some feedback of the previous version was that the tilemap movement was broken and the controls were all over the place.

This update was made to fix the majority of those complaints and improve the overall game feel. This includes the following:

- 3 new levels which introduce the player to the mechanics of the game (tooltips will be coming soon!)

- Added music during the playthrough of each level.

- Changed player movement, so it's normal movement instead of tilemap movement. I may change this back once I have a better idea of how to create a tilemap movement system. (I was considering using an array of tags for each particular tile in the tileset.)

- I have changed the way to select the bridge type. It used to be that the number buttons would be used to select a specific bridge type. Now you use the scroll bar (up and down) to select a bridge. 

- A new title screen, level select screen and thumbnail.

- Instead of changing the scene with the get_tree() function, I have created a system to load levels and player separately.

- Removed a bug where the player could delete the exit platform.

Future updates of the game will possibly include:

- Tooltips for the first couple of levels, which tell the player how the mechanics work.

- An options screen with options for music, visuals and maybe language

- Tileset movement for better game feel

- Different "Biome" types for each level (e.g. grass, desert, volcano, sea) with each their own music.

- A more detailed (and more formal looking) level select screen.

- Something secret!!