docs: Clarify weak source releasing

docs/sphinx/reference-sources.rst

@@ -789,10 +789,11 @@ General Source Functions
 .. function:: obs_weak_source_t *obs_source_get_weak_source(obs_source_t *source)
               obs_source_t *obs_weak_source_get_source(obs_weak_source_t *weak)
 
-   These functions are used to get a weak reference from a strong source
-   reference, or a strong source reference from a weak reference.  If
+   These functions are used to get an incremented weak reference from a strong source
+   reference, or an incremented strong source reference from a weak reference. If
    the source is destroyed, *obs_weak_source_get_source* will return
-   *NULL*.
+   *NULL*. Release with :c:func:`obs_weak_source_release()` or
+   :c:func:`obs_source_release()`, respectively.
 
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