Broken links in docs

[ChildishGiant]

Now we're hosting our own docs there are a few broken links due to it being at https://materializecss.github.io/materialize/ instead of https://materializecss.github.io/ (The easiest examples are the "get started" button and clicking on the materialize logo). I'm happy to open a PR to fix these or we could make a few changes (I'll open a PR for this too) and move it over. Third option: we get a custom domain which also would solve this.

[ChildishGiant]

I'm also happy to change the build script to publish at https://materializecss.github.io/ but that would require making another repo.