Updated all links to use https://www.authelia.com/docs/.
Removed all comment sections from documented configuration on the documentation site and replaced them with their own sections.
Made all documentation inside config.template.yml double hashes, and made all commented configuration sections single quoted.
Added .yamllint.yaml to express our desired YAML styles.
Added a style guide.
Refactored many documentation areas to be 120 char widths where possible. It's by no means exhaustive but is a large start.
Added a statelessness guide for the pending Kubernetes chart introduction.
Added labels to configuration documentation and made many areas uniform.
* implement SMTP notifier startup check
* check dial, starttls, auth, mail from, rcpt to, reset, and quit
* log the error on failure
* implement mock
* misc optimizations, adjustments, and refactoring
* implement validate_skip config option
* fix comments to end with period
* fix suites that used smtp notifier without a smtp container
* add docs
* add file notifier startup check
* move file mode into const.go
* disable gosec linting on insecureskipverify since it's intended, warned, and discouraged
* minor PR commentary adjustment
* apply suggestions from code review
Co-Authored-By: Amir Zarrinkafsh <nightah@me.com>