updated index.srt file tree structure to contain only existing parts
initial take on cde_reference.rst file
major takes on initial docs files.
initial take on test dir for data structures part of the grat core
initial take on hashed linked list test suite
 empty tests for hashed linked list test suite
 initial take on test for hashed linked list node
initial take on data structures package for core module
initial take on data structures module
typo correction
initial corrections
initial take on HLList data structure and supporting classes
last test revision for initial take on hashed linked list test case
initial take on exception/error classes for data structures package
initial take on hashed linked list implementation. Passes current test suit.
added equality test for HLLNode, as nodes must be compared by value and u_id
expanded equality test, as HLLNode must not be equal to any other type, but HLLNode
implementation of equality method, that passes respective test suite for HLLNode
added simple test for __str__ method for HLLNode object
added implementation of __str__ method that passes current test cases
expanded test for hashed linked list to support operation inversion
implemented the "reverse" method that passes current test suite