[Doc] fix several typos (#2603) #3480

Job	Run time
unittests-meltingpot / linux-job	6m 40s
unittests-pettingzoo / linux-job	8m 21s
unittests-atari-dqn (3.9, 12.1) / linux-job	6m 18s
unittests-brax (3.11, 12.1) / linux-job	10m 3s
unittests-d4rl (3.9, 12.1) / linux-job	5m 55s
unittests-envpool (3.9, 12.1) / linux-job	5m 48s
unittests-gendgrl (3.9, 12.1) / linux-job	5m 53s
unittests-gym (3.9, 12.1) / linux-job	8m 7s
unittests-jumanji (3.9, 12.1) / linux-job	8m 2s
unittests-minari (3.9, 12.1) / linux-job	5m 53s
unittests-open_spiel (3.9, 12.1) / linux-job	7m 56s
unittests-openx (3.9, 12.1) / linux-job	6m 9s
unittests-robohive (3.9, 12.1) / linux-job	7m 21s
unittests-roboset (3.9, 12.1) / linux-job	5m 46s
unittests-unity_mlagents (3.10.12, 12.1) / linux-job	8m 16s
unittests-sklearn (3.9, 12.1) / linux-job	5m 54s
unittests-smacv2 (3.9, 12.1) / linux-job	9m 50s
unittests-vd4rl (3.9, 12.1) / linux-job	5m 50s
unittests-vmas (3.9, 12.1) / linux-job	8m 19s
	2h 16m 21s

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