Update build 0.1.3.

In this build I mainly reworked the final phase inside the Cathedral and made some tweaks during previous phases:

• Since the cathedral phase seems too easy compared to what I originally planned for that section, I added an oxygen mechanic to reinforce the aesthetic and raise gameplay pacing. Most of the ledges were replaced to match better with the new mechanic and design purposes.
• Add a new type of ledge that will crumble after the player jumps up on another ledge. I want to use them mainly during the Cathedral section, to add more challenge and  interact better with the oxygen mechanic
• Fix some collisions and mesh positions in previous sections
• Add two platforms during the first section of the level to break the climbing flow 
• Add simple UI to display act progress during gameplay, showing act name and section name