legal2md Windows Command Prompt Partial Fix (I Think)

The text from my commit:

As Legal-Markdown-Sublime was processing files successfully, I cross-checked that repository's version of legal_markdown.rb against the version that was not working for me in the Legal-Markdown repository. There were differences, so I conformed the Legal-Markdown version to the Legal-Markdown-Sublime version.

That was progress, but not the end of the story. At the command prompt, `legal2md` was still throwing `NoMethodError` exceptions on the `@headers` in `leaders.rb`. This appears to be because my input file
lacked a complete set of YAML front-matter. Once I included at least placeholders for the three `Properties` headers (`no-indent`, `no-reset`, and `level-style`) I was successful in running `legal2md [input file] [output file]` and `legal2md -b [input file] [output file]` from the Windows 7 Command Prompt without it returning the previous error, which was: `Sorry, I could not read the file ["--headers", "test.lmd"]: no implicit conversion of Array into String.`

Commit `b2e30ef` adds a file or two from the Sublime repo, but it is not clear to me that those changes had any effect on the above.

I was running Ruby version 2.0.0p247.