Since polygons are essential in graphics, I added triangle as a struct
and added draw-functionality. Furthermore, I added getPos for this
struct.

By usage of trigonometric function, I was able to reduce the
computational complexity of the algorithm from O(r^2) to O(r).

Since the julian style convention is variables with only lower case
characters, functions with lower case and underscore, and structs with
camel case with upper case for the first letter, I changed files
according to this standard (with some exceptions). Furthermore I changed
some styling, like new lines in order to not go beyond 80 chars on one
line.

1. Removed parentheses around conditionals in while and if statements,
since it's more julian.
2. Made spelling more julian.
3. Changed tab size from 4 to 2, since most packages use this as
standard.
4. Respelled `schduler` to `scheduler` in exports.
5. Removed `line` from exports.
6. Moved Game-utilities from `GameZero.jl` to a separate file `Game.jl`,
and thus `GameZero.jl` only contains exports, imports and includes.
7. Restructured `GameZero.jl` to make it clear what it depend upon and
exports.
8. Moved Geom-utilities from `screen.jl` to a separate file `Geom.jl`.
9. Renamed `screen.jl` to `Screen.jl` since it represents a struct.
10. Made a folder for keyboard-utilities.
11. Moved every keyboard module to their own module-file.
12. Renamed `keyboard.jl` to `Keyboard.jl`, since it only contained
functionality for the Keyboard struct.
13. Made a folder for timer-utilities.
14. Created a file in `timer/` for WallTimer-utilities, and removed the
same content in `timer.jl`.
15. Created a file in `timer/` for Scheduled structs and utilities, and
removed the file `timer.jl`.
Creating modules to be separate files

In order to achieve more structure in the code.