Fixed a few misspelled words

docs/docs/instances.md

-## Building a not-persistant instance
+## Building a non-persistent instance
 
 
 In order to create instances of defined classes just do as follows. You might recognize the syntax if you coded Ruby in the past. Using the `build`-method will return an unsaved object, which you explicitly have to save.
 In order to create instances of defined classes just do as follows. You might recognize the syntax if you coded Ruby in the past. Using the `build`-method will return an unsaved object, which you explicitly have to save.
     
     
@@ -53,7 +53,7 @@ Task
   })
   })
 ```
 ```
 
 
-## Creating persistant instances
+## Creating persistent instances
 
 
 Besides constructing objects, that needs an explicit save call to get stored in the database, there is also the possibility to do all those steps with one single command. It's called `create`.
 Besides constructing objects, that needs an explicit save call to get stored in the database, there is also the possibility to do all those steps with one single command. It's called `create`.
     
     
@@ -102,7 +102,7 @@ task.updateAttributes({ title: 'foooo', description: 'baaaaaar'}, {fields: ['tit
 })
 })
 ```
 ```
 
 
-## Destroying / Deleting persistant instances
+## Destroying / Deleting persistent instances
 
 
 Once you created an object and got a reference to it, you can delete it from the database. The relevant method is `destroy`:
 Once you created an object and got a reference to it, you can delete it from the database. The relevant method is `destroy`: