Add leetcode stats card

[rickstaa]

Is your feature request related to a problem? Please describe.

The GRS repository currently doesn't have a way to show Leetcode statistics.

Describe the solution you'd like

I think including this card in the GRS card family will be nice.

Describe alternatives you've considered

A Leetcode card can be found at https://github.com/JacobLinCool/LeetCode-Stats-Card, but it would be nicer to have it available in the GRS repository so that the styling and themes of GRS can be used.

Additional context

No response

[anuraghazra]

Let's not do this, we can keep "github"-readme-stats for github only, We already have Wakatime card which I initially added without much thought. But adding more and more services / cards will only lead to increased maintenance efforts and downtimes.

[rickstaa]

@anuraghazra I agree. I think releasing the npm package so people can create cards based on our repository is a nice addition (see #2152). We can then even migrate to an organization and transfer cards well under that organization (see #1867).