fix document for associations

fix document for associations

docs/docs/associations.md

@@ -150,7 +150,7 @@ Project.belongsToMany(User, {through: 'UserProject'});
 User.belongsToMany(Project, {through: 'UserProject'});
 User.belongsToMany(Project, {through: 'UserProject'});
 ```
 ```
 
 
-This will create a new model called UserProject with with the equivalent foreign keys `ProjectId` and `UserId`. Whether the attributes are camelcase or not depends on the two models joined by the table (in this case User and Project).
+This will create a new model called UserProject with the equivalent foreign keys `ProjectId` and `UserId`. Whether the attributes are camelcase or not depends on the two models joined by the table (in this case User and Project).
 
 
 Defining `through` is required. Sequelize would previously attempt to autogenerate names but that would not always lead to the most logical setups.
 Defining `through` is required. Sequelize would previously attempt to autogenerate names but that would not always lead to the most logical setups.