I wrote a WordPress plugin that enables you to post an outline as an unordered list within a post or page. You can grab the code (and see attribution to Betsy Kimak, upon whose code this plugin is based) here. I just wrote it today so expect further development.
Copy the gist into a text file.
Title it fargo2opml.php
Create a folder called fargo2opml
Drag the file into the folder
Compress folder as zip file
Install it into a self-hosted WordPress site
Activate the plugin
Or remove the opening and closing php tags and drop it in your functions.php file.
In the content area of your WordPress post or page, just use this shortcode:
(Obviously, paste the URL of the OPML file between the quotes.)
I've tested this in a few blog installations, and for some the padding before the
ul is absent, so all headlines are "flat," i.e., not nested. But it works in both posts and pages in the default 2013 theme.
Also if a public URL starting with
https://dl.dropbox.com leads to parsing errors, paste the URL into the address bar, hit return, and use the updated URL that includes "dropboxusercontent" in the URL.