* Fix all markdownlint errors on README.md
* Add markdownlint to ci and makefile
* Fix all markdownlint errors on CHANGELOG.md
* Fix all markdownlint errors on CONTRIBUTING.md
* Fix all markdownlint errors on TODO.md
* Fix all markdownlint errors on docker/README.md
* Fix all markdownlint errors on docker/debug/HOWTO.md
* Fix all markdownlint errors on .github/ISSUE_TEMPLATE/bug_report.md
* Remove TODO.md
This commit introduces a new 'debug' build stage in the Dockerfile
to facilitate remote debugging for development environments.
It also includes a general reformatting of the Dockerfile
for better readability and maintainability.