* Create a constant for 'markdown' formatting style, to reduce duplicated strings and make the code less error-prone
* Unescape HTML entities from text messages
* Fix DOCS.md example configuration with custom message from file
* Move .test.message to a better named file
* Add support for additional, custom extra vars to be used in the message template
* Add cmdline/envvars to support the extra vars
* Enhance DOCS.md with example configuration using generic template file with custom vars
* Add testcase for custom template vars
Daniel M. Lambea