v0.9.0

What's changed?

feat(init): add init command and tag filtering for list/report by @coko7 in #6

• add boat init command that outputs a default config to stdout, useful
  for bootstrapping or recovering from a broken config. Improve error
  handling when config fails to load by printing a helpful message
  pointing users to boat init
• add --filter-by-tags (-t) flag to FilterActivitiesArgs, applied
  in both list and report commands to restrict output to entries
  matching all specified tags (closes #4)
• improve --period error messages by replacing the static string with
  a formatted help message showing all valid period presets and formats
• change default quick_start in generated config from false to true
• add comprehensive usage documentation for all commands

Full Changelog: v0.8.0...v0.9.0