doc: clarify variable

Co-authored-by: Luis Gustavo <[email protected]>

Author: fruitymedley

CONTRIBUTING.rst

@@ -113,7 +113,7 @@ Clone the repository
    page. This creates a copy of the code under your account on |the repository service|.
 #. Clone this copy to your local disk::
 
-    git clone [email protected]:YourLogin/strawberry-sqlalchemy-mapper.git
+    git clone [email protected]:YOUR_USERNAME_HERE/strawberry-sqlalchemy-mapper.git
     cd strawberry-sqlalchemy-mapper
 
 Install dependencies and plugins