updated READMEs + bug fix in low-level planner Enhanced CBS to now return correct lower bound after a path has been found + changed 'update_lower_bound' method since f_min can decrease during search process after expanding a state into neighbour states.

updated 'conflicting_single_agent_state' if-case + added Greedy search annotation comments to low-level 'greedy_plan' 'stastar_greedy_planner.py'

implementation greedy CBS (final) + Enhanced CBS + small unharmful change to 'safe_distance' function of original CBS planner needed for the conflicts heuristic implementation.

update README greedy-cbs + change conflicts_heuristic.py to check for one conflict between a state position when calculating an agents new path and other already existing agents paths (from the high-level CTNode solution) + Added comments.