Translated "Add React to an existing project" page content; fixed TOC's heading & sidebar#425

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deblasis merged 3 commits intoreactjs:mainfrom

Th3Wall:translations-add-react-to-an-existing-project-page

Apr 27, 2023

Commits on Apr 27, 2023

Translated page content; fixed TOC heading & sidebar

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Davide Mandelli
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