Update README.md: Improving understanding

About Cairo "builtins". 
I believe it's the complexity of operations that can be accelerated rather than the "complexity of builtins".
Similarly with "limiting" ... it is not on complexity but on the "range" of operations that can be accelerated.
I know, I know ... semantics! ;-)

README.md

@@ -37,4 +37,4 @@ We would like to acknowledge the projects below whose previous work has been ins
 - [Plonky3](https://github.com/Plonky3/Plonky3): The SP1's prover is powered by the Plonky3 toolkit.
 - [Valida](https://github.com/valida-xyz/valida): The SP1 cross-table lookups, prover, borrow macro, and chip design, including constraints, are inspired by Valida.
 - [RISC0](https://github.com/risc0/risc0): The SP1 rust toolchain, install/build scripts, and our RISCV runtime borrow code from RISC0.
-- [Cairo](https://docs.cairo-lang.org/how_cairo_works/builtins.html): Cairo introduced the idea of "builtins" which allow zkVMs to accelerate certain operations. However, the complexity of "builtins" was embedded in the CPU, limiting their complexity. SP1 extends this idea by executing on a vision of easily extensible "precompiles" that can be added as additional tables alongside the CPU.
+- [Cairo](https://docs.cairo-lang.org/how_cairo_works/builtins.html): Cairo introduced the idea of "builtins" which allow zkVMs to accelerate certain operations. But the “builtins” being embedded in the CPU limited acceleration to less complex operations. SP1 solves this restriction by extending the “builtins” idea to extensible “precompiles” that can be added as tables alongside the CPU.