-- breaking out code and tests for walka, list / tree walking
-- finished code and test for walka, which pretty-prints nested elements with attributes
-- for processing an element, adding a context-input-predicate, that ensures input is only :keywords or vectors of :keywords
-- added code and tests to join-nested-contexts
-- have a working repl version of walka - nested structures with nested contexts
-- fixed unit tests for walka and walkb
-- stiching in zengarden.core/css function to walka