Improve the out of the box experience

[joshuabenuck]

The out of the box experience currently requires users to understand some very obscure syntax. Once deno is installed, users must specify a directory of meta-sites or a single meta-site. For the majority of meta-sites, the hostname needs to be remapped. None of this is very intuitive.

To make the out of the box experience better, this issues proposes the following changes:

• If no parameter is specified, start seran-wiki on localhost and open the user's default web browser to a hosted page offering configuration options.
• Add support for a configuration file that allows for more complex configuration of meta-sites without requiring everything be specified as command line options.

Config UI recommendations:

• The config page should allow the user to make changes to the server.
• All changes should be persisted.
• Changes that can be applied without server restart should be.
• The user should be able to restart the server from within the configuration page.