Docs fix spelling issues

CHANGELOG.md

@@ -22,7 +22,7 @@ Entries are listed in reverse chronological order.
 ## 1.0.2
 
 * Updates the library to use the renamed functions in Merlin 1.1.
-* Adds additional validation checks to prevent identity points being used as
+* Adds additional validation checks to prevent identity points from being used as
   part of a proof.  This does not appear to have security content, but is
   intended as a defense-in-depth mechanism.  
   See [this comment][identity_comment] for more motivation.

docs/notes-r1cs.md

@@ -67,7 +67,7 @@ Then, the prover performs a combination of the following operations to generate
 
 Gadgets are buildings blocks of a constraint system that map to some functions in a higher-level protocol.
 Gadgets receive some [variables](#variables) as inputs, may [allocate more variables](#building-constraints) for internal use,
-and produce constrains involving all these variables.
+and produce constraints involving all these variables.
 
 Examples:
 * a **shuffle gadget** creates constraints that prove that two sets of variables are equal up to a permutation;

docs/r1cs-docs-example.md

@@ -50,7 +50,7 @@ The last multipliers connect the two last variables (on each side)
     muly_right[k-2] = y_{k-1} - z
 ```
 For `K = 1`:
-Connect `x_0` to `y_0` directly. Since there is only one permuatation of a 1-element list, we can omit the challenge entirely as it cancels out.
+Connect `x_0` to `y_0` directly. Since there is only one permutation of a 1-element list, we can omit the challenge entirely as it cancels out.
 ```ascii,no_run
     x_0 = y_0
 ```