Confluence.md

* documentation hotfix
* rename the default branch from master to main

* On-prem instances support (with user+password auth)

- hotfix: external images are working again

**Full Changelog**: https://github.com/szn/confluence.md/compare/v0.2.0...v0.2.1

- local images support

**Full Changelog**: https://github.com/szn/confluence.md/compare/v0.1.2...v0.1.3

- fix issue 3

**Full Changelog**:
2022-03-24 create --overwrite mode
2022-03-24 quiet mode
2022-03-20 cleanup readme (origin/master)
2022-03-20 add readme install guide