Fix typos and clean up leftover draft text in docs

[Chessing234]

Summary

• tokenize.md: Fix typo tokenzier.bos_token_id -> tokenizer.bos_token_id in the parameter table
• taggers.md: Fix "which is a the same" -> "which is the same" (2 occurrences) and "grapheme clusers" -> "grapheme clusters" (2 occurrences)
• data-format.md: Fix "The mixer create" -> "The mixer creates", "signal get" -> "signals get", clean up sentence casing, and remove leftover conversational draft text ("how does your signals data look?") and a stray } at the end of the file
• mixer.md: Fix "do not with to use" -> "do not wish to use"
• parallel-processor.md: Fix "into one might implement" -> "into how one might implement"
• getting-started.md: Remove misleading comment # run on 96 cores next to --processes 16

Test plan

• Verify all changes are typo/grammar fixes with no semantic changes
• Confirm no formatting is broken in rendered markdown

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