Updated Performance (markdown)

Performance.md

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+> Read carefully before you jump to conclusions on this page! 😄
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 There are easy ways to configure TypeScript to ensure faster compilations and editing experiences.
 The earlier on these practices are adopted, the better.
 Beyond best-practices, there are some common techniques for investigating slow compilations/editing experiences, some common fixes, and some common ways of helping the TypeScript team investigate the issues as a last resort.