Update index.ts

[aasim-syed]

In update

• [x] it uses the path.join() method to join path segments instead of concatenating them with the sep constant, which makes the code more platform-independent and less error-prone.

• [x] It generates a unique file name using the current timestamp and a random number, which reduces the chance of file name collisions and improves security.

• [x] It uses the tmpdir() function from the os module to get the path of the system's temporary directory, which is a more reliable way of getting the temporary directory path than hard-coding it.

• [x] It writes the code to the file stream, which is a more memory-efficient way of writing large or complex code strings to a file.