Add examples from zig-benchmarks-game

[chung-leong]

• [x] binary-trees
• [x] fannkuch-redux
• [x] fasta
• [x] k-nucleotide
• [x] mandelbrot
• [x] n-body
• [x] reverse-complement
• [x] spectral-norm

[chung-leong]

Not implementing pidigits and regex-redux since they rely on C libraries