Add server mode

[yhatt]

This PR will add server mode provided by --server (-s) option. It would apply the on-demand conversion to the served markdown files.

Server mode recognizes a directory passed by --input-dir option to keep structure.

marp -s --input-dir slide

If you have a markdown in ./slide/markdown.md, you can trigger the on-demand conversion by accessing to http://localhost:8080/markdown.md or http://localhost:8080/markdown.html.

To provide the user-friendly CLI interface, an inputed argument treats as the input directory even without --input-dir (-I) option when there is --server (-s) option. Thus, the below command would work as same too.

marp -s slide

The default port number is 8080. It could change by PORT environment variable as same as many server programs.

Docker

docker run --rm --init -v $PWD:/home/marp/app/ -p 8080:8080 -p 52000:52000 marpteam/marp-cli -s slide

Related to yhatt/marp#232.

ToDo

• Add tests