LCC2 is N-ary tree, not octree

In the Supported Formats table, the description of .lcc2 currently states it is an octree format.
However, according to the official LCC2 whitepaper ([https://github.com/xgrids/LCC2Whitepaper](https://link.wtturl.cn/?target=https%3A%2F%2Fgithub.com%2Fxgrids%2FLCC2Whitepaper&scene=im&aid=497858&lang=zh)), LCC2 is defined as an N-ary tree instead of an octree.