Small update - no more dead ends

This update forbids you from placing tiles which create dead-ends. Now the only way to "close off" parts of the map is by making a full loop.

As a result of this change, it became possible to be in a situation where you were physically incapable of placing any of your tiles, softlocking the game. To fix this, the game will automatically detect these "deadlock" situations, and give you the option to "skip" tiles in order to progress through the game. This is a bit of a janky solution but my hope is that it is rare enough that most players would never see it.

PS: This is also my first devlog post! Just a minor update for now, but I plan to write some more longform posts in the future, so stay posted.