Docs fix spelling issues (#152)

* Update nimfs.rs

* Update utils.rs

---------

Author: nnsW3

folding-schemes/src/folding/hypernova/nimfs.rs

@@ -667,7 +667,7 @@ pub mod tests {
     }
 
     /// Test that generates mu>1 and nu>1 instances, and folds them in a single multifolding step
-    /// and repeats the process doing multiple steps.
+    /// and repeats the process by doing multiple steps.
     #[test]
     pub fn test_multifolding_mu_nu_instances_multiple_steps() {
         let mut rng = test_rng();

folding-schemes/src/folding/hypernova/utils.rs

@@ -177,7 +177,7 @@ pub mod tests {
     use crate::utils::mle::matrix_to_dense_mle;
     use crate::utils::multilinear_polynomial::tests::fix_last_variables;
 
-    /// Given M(x,y) matrix and a random field element `r`, test that ~M(r,y) is is an s'-variable polynomial which
+    /// Given M(x,y) matrix and a random field element `r`, test that ~M(r,y) is an s'-variable polynomial which
     /// compresses every column j of the M(x,y) matrix by performing a random linear combination between the elements
     /// of the column and the values eq_i(r) where i is the row of that element
     ///