Clarify binding name collisions

Because service bindings are inherently decentralized, there is no way
to universally detect a name collision. Users are encouraged to avoid
colliding names as the behavior is undefined by the spec.
Implementations may check for known collisions to display a more
meaningful to the user, but detection cannot be guaranteed as it's at
best a good faith attempt.

Signed-off-by: Scott Andrews <[email protected]>

Author: scothis

README.md

@@ -206,6 +206,8 @@ The name of a binding entry file name **SHOULD** match `[a-z0-9\-\.]{1,253}`.  T
 
 The collection of files within the directory **MAY** change during the lifetime of the container or between container launches.
 
+Users **SHOULD** ensure each binding has a unique name.  The behavior for name collisions is undefined.  Implementations **MAY** attempt a good faith check for collisions to provide a meaningful error message.
+
 ## Example Directory Structure
 
 ```plain