Omnihost

Added
- Containerize omnihost
- Add an example bash script to make running the containerized script more convenient
- Add support for env variables or a config file instead of requiring file paths to be passed on the command line every single time

Fixes
- Properly escape special characters in html output

Changed
- Add custom exception types to improve error handling
- Add logging

Fixes

- Fix internal links so that the html pages no longer point to gemini pages
- Change program name in CLI help output from 'omniconverter' to 'omnihost'

Added

- A sane deployment process. Omnihost is now available from pypi.org, installable via pip. Instructions for installation and usage have been updated in the README
- This CHANGELOG!

Changed

- Dependencies are now managed via `poetry`. Project and dev dependencies have been separated and are listed in `[tool.poetry.dependencies]` and `[tool.poetry.dev-dependencies]` respectively. This obviates the need for requirements.txt
- Updated roadmap in README to reflect changes

Added

- Initial release with basic functionality
+ Ability to convert gemtext markup files to html
+ Ability to specify a stylesheet to be applied to generated html files
- Limitations of initial release
+ No ability to generate gophermaps. A gophermap output directory can be specified, but no action will be taken
+ No support for a nested source or output directory structure. All gemtext files to be converted must be at the top level of the input directory
+ Complicated deployment story. v0.1.0 must be cloned from the repo and run directly.
+ Limited error handling
+ No automated tests, all testing so far has been manual on a subset of functionality
+ No logging