docs(afs): typo, misspelled word 'methods' #1213

docs/firestore/documents.md

@@ -72,7 +72,7 @@ There are multiple ways of streaming collection data from Firestore.
 
 **Why would you use it?** - When you just need the object data. No document metadata is attached which makes it simple to render to a view.
 
-**When would you not use it?** - When you need the `id` of the document to use data manipulation metods. This method assumes you either are saving the `id` to the document data or using a "readonly" approach.
+**When would you not use it?** - When you need the `id` of the document to use data manipulation methods. This method assumes you either are saving the `id` to the document data or using a "readonly" approach.
 
 ### `snapshotChanges()`
 **What is it?** - Returns an Observable of data as a `DocumentChangeAction`. 
@@ -106,4 +106,4 @@ To retrieve a nested collection use the `collection(path: string)` method.
   }
 ```
 
-### [Next Step: Collections in AngularFirestore](collections.md)
+### [Next Step: Collections in AngularFirestore](collections.md)