add BigInt content (JS) (#6397)

* add BigInt content (JS)

* Update src/data/roadmaps/javascript/content/bigint@6lUF0neW1piiP1RsaVxEX.md

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Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

src/data/roadmaps/javascript/content/bigint@6lUF0neW1piiP1RsaVxEX.md

@@ -1 +1,10 @@
-# bigint
+# bigint
+
+BigInt is a built-in JavaScript object that allows you to work with integers of arbitrary size.
+
+Unlike the Number type, which can accurately represent integers only within the range of ±2^53 , BigInt can handle integers far beyond this limit. This makes it particularly useful for applications requiring high precision with very large numbers, such as cryptography or scientific computations.
+
+Visit the following resources to learn more:
+
+- [@article@BigInt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt)
+- [@video@The Whys and Hows Of BigInt](https://youtu.be/6I650PQfhMg?si=XyVGrmp4KWLRcHVj)