📝 refine changelog for v2.4.1

v2.4.0

- Add an `export` command to export gist to an existing git repo.
- `sync` can also clone repository with https protocol (controlled by an
environment variable).
- `sync` can auto commit changes if the gist repo is dirty (controlled
by an environment variable).

- New command `check` to report dirty repositories.

- `sync` also sync starred gists.
- Use legit to do smart merge if available.
- Less verbose output.
- Fix a bug regarding gist home path expansion.
- Replace Rake with make.

- sync: skip sync dirty repos, warn instead.

- sync: change UI to report non-modified gist.
- update repo/$gist_id/config for deleted gists
- Fall back to `grep` if codesearch is not available.

Release v2.1.2

doc about marking deleted gist

fix #7

sync_gist(): more friendly output

Fix a bug that causes `gister` to fail if no token.

There is a bug that if a user did not have  a token already, gister would fail.
Thanks to wenLiangcan.

fetchall(): fix a serious bug which fails cloning

The clone address should be `[email protected]:gist_number.git`.

Release 1.0.0