doc: copyedit maxBuffer note for child_process

PR-URL: https://github.com/nodejs/node/pull/6760
Reviewed-By: Roman Klauke <romaaan.git@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

doc/api/child_process.md

@@ -1040,9 +1040,9 @@ to the same value.
 ## `maxBuffer` and Unicode
 
 It is important to keep in mind that the `maxBuffer` option specifies the
-largest number of *octets* allowed on `stdout` or `stderr` - if this value is
+largest number of *octets* allowed on `stdout` or `stderr`. If this value is
-exceeded then the child process is terminated. This particularly impacts
+exceeded, then the child process is terminated. This particularly impacts
-output that includes multi-byte character encodings such as UTF-8 or UTF-16.
+output that includes multibyte character encodings such as UTF-8 or UTF-16.
 For instance, the following will output 13 UTF-8 encoded octets to `stdout`
 although there are only 4 characters: