Update to bevy 0.14.0

[barafael]

Tried to keep a minimal diff. I'm not sure the system precedence is same as in the 0.7.0 version, with regards to the FoodTimer.

[lcdss]

Even it never gets merged, thank you so much for this PR. I was following the blog post and the API had several changes version after version and I couldn't find enough information in the docs and in the release notes to fix the code.

[barafael]

Same thing happened to me! Hence the changes :D the bevy changelog helped. How did you find the tutorial?

[lcdss]

Same thing happened to me! Hence the changes :D the bevy changelog helped. How did you find the tutorial?

I was looking at the bevy website and found a list of games implemented using the library and I liked the snake game example as I was a great fan in the past. The changelog helped but I got stuck trying to fix the usage of add_system_set_to_stage and decided to look if there was an issue or PR with an updated implementation.