fix: change delimiter from : to ,

chore: complete Cargo.toml

feat: add copy_to and move_to functions

feat: add remove_flag function

chore: organize errors in error module

feat: add proper folder support

refactor: shorten parse_month function

refactor: restructure public API and add more docstrings

chore: rename "messages" methods to "entries"

chore: fix clippy lints

test: add checksum unit test

fix: oversights

feat: parse datetime and use in human-centric part

docs: flesh out docstrings

feat: allow setting metadata for Entry

feat: implement delivery

feat: move m2store to own module and prepare deliver

feat: M2dir from path and move to separate module

style: add rustfmt.toml

refactor: separate out Entry into own module