update license

final touches, readme and license

docs: add README with plugin description and usage instructions

style: Remove unused background option from window config

refactor: update deprecated nvim_win_set_option to nvim_set_option_value

fix: set window background to match Normal highlight group

style: Add trailing comma in window config

feat: add background inheritance to timer window

style: Format window title string construction for better readability

feat: implement session tracking and window title updates

style: Format state.lua with tabs instead of spaces

fix: update buffer and window option calls to use nvim_set_option_value

fix: improve buffer validation and error handling for pomodoro UI

fix: replace nvim_buf_set_option_value with nvim_buf_set_option

refactor: Update deprecated nvim_buf_set_option calls to nvim_buf_set_option_value