nofib-compare: Fix header of Markdown output

I noticed that the current output is all garbage, e.g. benchmark names (row headers) were used as column headers and we generated waaay to many column header separators, namely one for each character in the header line.

added 2 commits

• 98c4eabd - 1 commit from branch master
• 0841b424 - nofib-compare: Fix header of Markdown output

Compare with previous version

I will trust you on that one.

enabled an automatic merge when the pipeline for 0841b424 succeeds

aborted the automatic merge because target branch was updated

added 12 commits

• 0841b424...24a179b1 - 11 commits from branch master
• dd349233 - nofib-compare: Fix header of Markdown output

Compare with previous version

merged