platformer example

Ok, so this my 1st take on the platformer thing, stripped of jquery, requirejs and ecs stuff. Surprisingly over 300 lines, I thought it was going to be more like 100.

Any way, the platform model / texture is by me, as far as I remember (5 years old). Since I do not remember where that lava skybox was from, I used the skybox that already exist in 3js instead, so no copyright problems for you. Also converted json to v4 as I noticed you said you were going to deprecate v3 somewhere.

For code formatting, I stuffed extra space between () and parameters everywhere, but maybe missed a place or two. I seem to remember @mrdoob was asking for some sublime plugin to format the code into 3js style, did he find one?
a ha, except than in this case you can't really shoot. the blog post I was aiming for, the idea was to discuss not using any physics lib in favor of raycasting. but then again, I guess your typical "platformer" never has 1st person camera... except for maybe [this](https://www.youtube.com/watch?v=KBb9wFP7uZM). any way, I can rename it if you insist :panda_face: