API documentation expanded with status code information

Information to return codes added to projects and users documentation.

doc/api/projects.md

@@ -57,6 +57,11 @@ GET /projects
 ]
 ```
 
+Return values:
+
++ `200 Ok` on success and a list of projects
++ `401 Unauthorized` if the user is not allowed to access projects
+
 
 ### Get single project
 

doc/api/users.md

@@ -43,6 +43,12 @@ GET /users
 ]
 ```
 
+Return values:
+
++ `200 Ok` on success and a list with all users
++ `401 Unauthorized` if user is not allowed to access the list
+
+
 ## Single user
 
 Get a single user.
@@ -74,6 +80,13 @@ Parameters:
 }
 ```
 
+Return values:
+
++ `200 Ok` on success and the user entry
++ `401 Unauthorized` if it is not allowed to access the user
++ `404 Not Found` if the user with ID is not found
+
+
 ## User creation
 Create user. Available only for admin