init wiki
Add 'wiki/' from commit 'e668670434e82064a999a845443f923533681cd8'

git-subtree-dir: wiki
git-subtree-mainline: 40e1546249cee488a4b44f3e2488b914e2aeed90
git-subtree-split: e668670434e82064a999a845443f923533681cd8