WIP
Generate markdown footer links.
### Example:
```markdown
- [md-footer](https://github.com/sayanarijit/md-footer)
- `[ignoreme](https://link.to.ignore)`
[](https://github.com/sayanarijit/xplr)
```
Will convert into
```markdown
- [md-footer][1]
- `[ignoreme](https://link.to.ignore)`
[![xplr][2]][3]
[1]:https://github.com/sayanarijit/md-footer
[2]:https://s3.gifyu.com/images/xplr-0.5.0.gif
[3]:https://github.com/sayanarijit/xplr
```
### Usage:
```bash
# or
md-footer /path/to/file.md
```
It was used to [generate footer links for the xplr book](https://github.com/sayanarijit/xplr/pull/294/files).