Handle local files, thanks binarycat!

Add plumber rule in README (thanks fulton)

From b9f54564d6fee7515b7a4981f2eef6c121bf7e0d
From: Fulton Browne <git@fulton.software>
Date: Fri, 26 Mar 2021 21:23:17 +0000
Subject: [PATCH] Added plumbto gemini listener

With code adapted from phil9's gopher, castor9 can now recive messages from the plumber via plumbto gemini.

Remove url->raw and use fmt, remove undescores from names

Fixes:
- a misordered nil check in saneurl()
- an fd leak in gemini_get()
- a lack of base url in gemini_get()
thanks Ori!

Formatting

Add resettitle()

Can edit current URL

Add/Show bookmarks

Bookmark a page, refact current_url stuff

Remove castor.6

Move base_url in url.c

Move replace_char to util.c

Handle inputs

Fix mailto: links and relative URLs starting with a /

Add some comments before refact

Fix absolute URLs parsing and mailto

Adds a few regression tests for parseurl

Fixes mailto: URI handling

Allows URIs without a host segment, such as mailto: to be correctly
parsed.  Also passes only the path of mailto urls to the plumber to
match the default rule.

Add a README