docs: fix command substitution syntax in docker run example

[devin-ai-integration]

Jira issue(s): SUPPORT-14384

Changes:

• Fix incorrect shell syntax ($pwd) to $(pwd) in the docker run example for *nix systems

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Context: A user reported that the documented command docker run -v ($pwd):/data ... doesn't work because ($pwd) is invalid bash/zsh syntax. The parentheses start a subshell rather than command substitution.

Validation: Tested both syntaxes:

• echo ($pwd) → bash syntax error / zsh "no matches found"
• echo $(pwd) → correctly outputs current directory path

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Link to Devin run: https://app.devin.ai/sessions/0e13269b3bd64927b775c5dce5ec9653
Requested by: olena.marchuk@keboola.com

[devin-ai-integration]

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[OlenaMarchuk]

Devin created this PR to fix the documentation example for the Generic Extractor, specifically the sample shown here:
https://developers.keboola.com/extend/generic-extractor/running/#run-built-version