add more heading levels

[42sol-eu]

modified: mdpre

• add a log() to stderr funtion (with partials)
• add parameter for heading character
• process headings dynamically (character counting)

new file: tests/run_user-guide.bat

• only a note for windows testers

[42sol-eu]

Hi Martin,

this is the change.

I am not sure if you like my naming and documentation style. Feel free to reject then I will keep your style.

Sincerely Andreas

[MartinPacker]

Thank you! Will test further having merged. (I assume your test script proved a happy event.)

[MartinPacker]

You'll want to pull mdpre again. I just set us up for v0.4.6.

Closing now as my testing was fine.