Roff output force-adds a specific NAME section

[adminspotter]

My markdown documents have their own NAME sections, because I want them to look mostly like manpages before I do any processing on them. ronn adds another NAME section, even though one already exists.

Testing file:

# Test #

## NAME ##

test - the test manpage

## DESCRIPTION ##

Testing items.  w00t!

ronn invocation:

$ ronn --roff --pipe --name 'Testing' --section=9 --manual='Testing manual' --organization='Testers, Inc.' --date='2019-08-19' < test.md > test.9

Manual output:

TESTING(9)                      Testing manual                      TESTING(9)

NAME
       Testing - Test

NAME
       test - the test manpage

DESCRIPTION
       Testing items. w00t!

Testers, Inc.                     August 2019                       TESTING(9)

It looks like there's some logic in Ronn::Document to handle the various ways in which the document name can enter the processing, but they seem to assume that they should always add a NAME section. If I move the contents of my NAME section into the top header in the Markdown document, and drop the --name command line flag, ronn will format the resulting manpages correctly, but I lose the manpage format - specifically the NAME section - that I want in the original Markdown documents.

[apjanke]

Coincidentally, another user just emailed me about this last week.

I think we probably need a --no-name option to suppress automatic NAME section generation for cases like this. And maybe more probing for the existence of an explicit NAME section in the input.

[adminspotter]

The ideal situation would be if ronn was able to notice whether the section was there or not, and add it if necessary. As I was exploring the ronn source, that's what I had in mind, but was never able to find how that new NAME section got injected into the document source.

[adminspotter]

I've recently picked this back up and did some more hacking, and I think I've got the fix. I went in the direction of having ronn be able to figure things out on its own, rather than requiring any new command-line arguments. The Ronn::Document::sniff method gets some expansion, and then there's some small tweakage to Ronn::Document::html_filter_inject_name_section.

I need to add a unit test for the name injection method, and then I'll have a PR for you to look at.