Update c26430.md

Made some fixes that would have showed up on acrolinx, and simplified the language a little.

Author: TylerMSFT

docs/code-quality/c26430.md

@@ -68,7 +68,8 @@ void merge_states(gsl::not_null<const state *> left, gsl::not_null<const state *
 
 ## Heuristics
 
-The rule does not enforce every dereference of a pointer to have a prior null check to ensure the pointer is not null. Instead, it requires a null check before first derefernce of the pointer. So, the following function does not trigger a C26430 warning:
+This rule doesn't enforce every dereference of a pointer to have a prior null check to ensure the pointer isn't. Instead, it requires a null check before first dereference of the pointer. The following function doesn't trigger C26430:
+
 ```cpp
 void f(int* p)
 {
@@ -77,7 +78,9 @@ void f(int* p)
     *p = 2;
 }
 ```
-But the following function gets a C26430 warning because there is a path without null check for p to where *p is assigned with 2:
+
+The following function generates C26430 because there's a path to assign `*p` without a null check:
+
 ```cpp
 void f(bool b, int* p)
 {
@@ -86,11 +89,12 @@ void f(bool b, int* p)
     *p = 2;
 }
 ```
+
 Rules [C26822](c26822.md) and [C26823](c26823.md) apply to dereferencing a (possibly) null pointer.  
 
-The rule doesn't have full data flow tracking. It can produce incorrect results in cases where indirect checks are used (such as when an intermediate variable holds a null value and is later used in a comparison).
+This rule doesn't have full data flow tracking. It can produce incorrect results in cases where indirect checks are used, such as when an intermediate variable holds a null value and is later used in a comparison.
 
 ## See also
 
 [C26822](c26822.md)\
-[C26823](c26823.md)
+[C26823](c26823.md)