This change implements yamllint and adjusts all yaml files to abide by our linting setup. This excludes config.template.yml as this will be done in an alternate commit.
* [MISC] Append log file instead of overwriting
If Authelia is restarted when a `log_file_path` is defined upon restart the log file is overwritten as opposed to appending the existing file.
This change ensures that the log file will be appended to, users will need to ensure that they rotate/truncate this over time especially if running in `debug` or `trace`.
* Amend documentation for log_file_path
James Elliott
Amir Zarrinkafsh