Update writing_queries.md to fix grammar

Sounded weird.

docs/content/en/docs/Getting started/writing_queries.md

@@ -119,8 +119,8 @@ Future update(Todo entry) {
   // using replace will update all fields from the entry that are not marked as a primary key.
   // it will also make sure that only the entry with the same primary key will be updated.
   // Here, this means that the row that has the same id as entry will be updated to reflect
-  // the entry's title, content and category. As it set's its where clause automatically, it
-  // can not be used together with where.
+  // the entry's title, content and category. As its where clause is set automatically, it
+  // cannot be used together with where.
   return update(todos).replace(entry);
 }
 
@@ -258,4 +258,4 @@ Future<void> trackWord(String word) {
 Note that this requires a fairly recent sqlite3 version (3.24.0) that might not
 be available on older Android devices when using `moor_flutter`. `moor_ffi`
 includes the latest sqlite on Android, so consider using it if you want to
-support upserts.
+support upserts.