* Fix dockerfile.
It was broken because the practicerom package changed stuff and apt didn't like whatever changed.
This is the commit that seems to have broken how the old practicerom package worked: https://github.com/glankk/n64/commit/e7bec93b0b11b37a63abcf5ac28728f2fcd4045b#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5
* Update docker docs.
Some references were broken in the markdown files, and there's no longer a need to run the git `safe.directory` command since the docker file was doing it already
* Include `gcc-mips-linux-gnu` in the dockerfile
* break up dockerfile commands a bit more
* Update practicerom instructions
* Update practice rom again