Add roadmap migrator command

src/roadmaps/javascript/content/112-javascript-asynchronous-javascript/103-callbacks/readme.md

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+# Callbacks
+
+A callback function is a function passed into another function as an argument, which is then invoked inside the outer function to complete some kind of routine or action.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://javascript.info/callbacks'>Callbacks in JavaScript</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Glossary/Callback_function'>Callback Functions</BadgeLink>