[DG] Fix how to run path

[alilloig]

Description

Path under How To Run section is refering the old struct where the doc-gen tool was under the general cadence repo

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• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[turbolent]

Thanks!