chore(docs): add update-docs.sh script

docs/update-docs.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+if ! [[ $(git rev-parse --show-toplevel 2>/dev/null) = "$PWD" ]]; then
+    echo "error: script should be run from the root of the repository"
+    exit 1
+fi
+cp README.md docs/index.md
+find docs -name "*.md" | while read page
+do
+    sed -i 's/docs\/img/img/g' $page
+done