Write slides about merge with conflict

shell/fix-complex-merge

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+DIR="$(dirname "$(readlink -f "$0")")"
+cd /tmp/demo
+cp "${DIR}/../code-examples/python-merged.py" greeting.py > /dev/null
+echo '$ vim greeting.py'
+echo '  # Fix the conflict(s) #'
+echo '$ git add greeting.py'
+git add greeting.py
+echo '$ git commit'
+git commit -F .git/COMMIT_EDITMSG
+echo '$ git log --oneline --all --graph'
+git -c color.ui=always log --oneline --all --graph --decorate=short
+