remove resolved ideas from readme

i consider all removed notes that have not been implemented
bad (at least for now) ideas.

README.rst

@@ -20,23 +20,8 @@ todo and ideas
 note: this is just a braindump, not a check list. some ideas may not
 be good ideas after all and may never make it into this library.
 
-* write docs and docstrings
-
-* slice syntax to get containers out as built-in (not sanest counterpart) types
-
-  * d['a', 'b'::list] same as d['a', 'b':list].to_list()
-  * d['a', 'b'::dict] same as d['a', 'b':dict].to_dict()
-
 * nested walk helpers dict.walk() and list.walk()
 
-* json helpers
-
-* sanity checks that prevent creating circular references
-
-  * possible at all? no complicated parent(s) tracking please
-
-* dotted path strings or other separator? is this a good idea at all?
-
 * configurability
 
   * maybe factory helper that produces two custom classes?
@@ -49,13 +34,6 @@ be good ideas after all and may never make it into this library.
   * sanest.dict.readonly()
   * what about mixing?
 
-* identity checks fail when repeatedly getting the same container
-  because of the wrapping. keep cached WeakValuesDict for any wrapped
-  structures handed out?
-
-* have a ``check=False`` everywhere values can be set, not just in
-  ``.wrap()``
-
 * maybe list.contains() with type= arg that checks provided value
   while also checking containment