Log Message:
www/hackernews-tui: update to 0.6.1

Application changes:
-remove q,w,e,r default shortcuts/functionalities used to filter stories by
past date
-add support for defining custom shortcut to navigate between different
StoryView with filters

Codebase changes:
-implement support for defining custom keymap.
-minor improvements, bug fixes
-add Derive(Debug) for most of the defined structs
-move src/view/utils.rs to src/utils.rs
-refactor HelpView to allow non-static description for a key shortcut