this is a draft
ssg converts markdown files to html with marked.js,
copies *.html files with <html> tag as they are. for the rest of *.html
files ssg extracts their titles from <h1> tag, prepends ./.header.html,
appends ./.footer.html, copies everything to <dst> directory, and generates
<dst>/sitemap.xml. ssg ignores .* files and file paths listed in
./.ignore.
watch ./src directory and listen on port 1111/1112 (http/ws)
$ npx @rgzee/ssg watch src -p 1111 -w 1112 listening http://192.168.1.1:1111 websocket ws://192.168.1.1:1112 watching /home/rgzee/src
build from ./src into ./dst directory
$ npx @rgzee/ssg build src dst $