doc fix issue Update mod.rs

[Guayaba221]

Hey !
I fixed spelling issue.Glad I could help .
Br, Guayaba221.

[reviewable-StarkWare]

This change is 

[orizi]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @Guayaba221)

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crates/cairo-lang-casm/src/hints/mod.rs line 186 at r1 (raw file):

    /// in sqrt0 and sqrt1 as well as the 128bit limbs of the remainder in remainder_low and
    /// remainder_high. The remainder is defined as `value - sqrt**2`.
    /// Lastly it checks whether: `2*sqrt - remainder >= 2**128`.

Suggestion:

    /// Lastly it checks whether `2*sqrt - remainder >= 2**128`.

[Guayaba221]

@orizi Thanks. Done