docs: added examples for modules usage in Medusa (medusajs#5753)

* Add data migration script after running migrations

* Update install-medusa.mdx

* Update examples.md (medusajs#5751)

* fix lint errors

* fix comment in example

* added examples for modules usage in Medusa

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Co-authored-by: Riqwan Thamir <[email protected]>

Author: shahednasser