Markdown exporter (requirements only)

[kaklakariada]

This was requested by @tjaehnel.

Is your feature request related to a problem? Please describe. It should be possible to export spec items in Markdown format.

Describe the solution you'd like

1. The Markdown export shall only export requirements, i.e. no coverage tags from source code.
2. The spec items must be written in the same order in which they where imported.

Additional context The proposed use case is to

1. import a third party spec (e.g. in pdf format)
2. export the requirements in Markdown format
3. Manually update the Markdown file (e.g. add required coverage)
4. Use the Markdown file for tracing

[redcatbear]

@tjaehnel , I am guessing this topic is not relevant anymore (sorry for picking up on the ticket so late). Can we close this ticket?