doc: add rationale
## Assumptions
-Elektra is useful with only 3 types of global plugins:
-
+- Elektra is useful with only 3 types of global plugins:
- mmap
- spec
- notification
+- There are not too many types of global plugins, not more than 10
## Considered Alternatives
@@ -37,6 +37,12 @@ Elektra is useful with only 3 types of global plugins:
Have hooks specific to mmap, spec and notification.
These hooks are not shared, so no `list` plugin is needed.
+## Rationale
+
+- allows adding more types of plugins later, also post-1.0
+- much clearer semantics for each type, no need to compromise
+- easier to implement
+
## Implications
- remove `list` plugin
