[tbx11k] Implements database, improves documentation

src/ptbench/data/tbx11k_simplified_v2/fold_3.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_3.py

src/ptbench/data/tbx11k_simplified_v2/fold_4.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_4.py

src/ptbench/data/tbx11k_simplified_v2/fold_5.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_5.py

src/ptbench/data/tbx11k_simplified_v2/fold_6.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_6.py

src/ptbench/data/tbx11k_simplified_v2/fold_7.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_7.py

src/ptbench/data/tbx11k_simplified_v2/fold_8.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_8.py

src/ptbench/data/tbx11k_simplified_v2/fold_9.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_9.py