Could you please provide a small example how to use this module? For example in a node.js environment?

Use attaswift/BigInt as an inspiration for updating the README.

Also, make sure that the README is compatible to be used as the main page for the documentation generated by Doxygen (see #50).

Describe the bug
README is not well structured

To Reproduce
Look at README file

Expected behavior
README should provide a quick overview what the library provides, way to contribute. Detailed descriptions should be moved to Wiki

The WriteChar method correctly fails when attempting to write a surrogate character. However, it may be beneficial to have a better explanation saying that a single surrogate character can't be written and to consider using WriteValue with a character array.

To start with, it should handle 1-dimensional functions of these types:

• Polynomials (ax + b)
• Exponentials (a * b^x)
• Logarithmic (b log a)

Should be able to:

• Provide the derivative function
• Provide the integral function

Seen with @arnetheduck.

for uint128, stint properly generates add + adc (see status-im/nim-stint#10)

But for uint256+, the way carry is done will loop multiple time on the low half
https://github.com/status-im/nim-stint/blob/9993b9dca4a2dbf76bc432252ad4e8db944ae831/stint/private/uint_addsub.nim#L17-L29

Important for WASM codesize optimization.

• Benchmark suite.
• Compare with Rust.
• Compare with incoming javascript's BigInt.

I'm going to procrastinate on this until Razenpok does it probably