Squashed 'content/writing-research-markdown/research-markdown/' content from commit 1bd9d55

git-subtree-dir: content/writing-research-markdown/research-markdown
git-subtree-split: 1bd9d5581cfb463b70a2d92f4bcb0c7d6fe2dd59
Merge commit '17fe84635319dbb86afd31e6dc8b5997df759c4f' as 'content/writing-research-markdown/research-markdown'
add install header