Add support for footnotes

[adam-p]

This has been asked for by two different users via email.

Below is the hack-tastic workaround advice I gave.

---

I thought of a bit of a hack you can use to emulate your footnotes: put inline HTML <sup> tags¹. What I just did there looks like this: <sup>1</sup>. Then you can put a numbered list² at the bottom with the actual footnotes.

The numbered list in your original email had a larger left-side margin than mine will, but you could modify your "Primary Styling CSS" in the MDH options to and add something like margin-left: 10em; to the ol rule. But then it'd be like that for all your numbered lists.

You also have the carriage-return-ish icon in your footnotes at the bottom, but they're not links that lead back to the anchor, so... maybe you don't need them? If you want to add them by hand you can use the HTML entity³ ↵. Like so: ↵

I haven't been using the square brackets around the footnote super numbers because there's a danger of them ending up being reference-style MD links⁴. Like this¹¹ but not like this^[12].

Anyway, maybe this will help you and maybe it won't. It's probably more hassle than you're happy with. I'll include the raw version of this email below so that you can see it.

1. Gratuitous link to info about the <sup> tag: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/sup
2. MD cheatsheet entry for lists
3. List of HTML entities
4. https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet#links

---

I thought of a bit of a hack you can use to emulate your footnotes: put inline HTML `<sup>` tags<sup>1</sup>. What I just did there looks like this: `<sup>1</sup>`. Then you can put a numbered list<sup>2</sup> at the bottom with the actual footnotes. 

The numbered list in your original email had a larger left-side margin than mine will, but you could modify your "Primary Styling CSS" in the MDH options to and add something like `margin-left: 10em;` to the `ol` rule. But then it'd be like that for all your numbered lists.

You also have the carriage-return-ish icon in your footnotes at the bottom, but they're not links that lead back to the anchor, so... maybe you don't need them? If you want to add them by hand you can use the HTML entity<sup>3</sup> `&crarr;`. Like so: &crarr;

I haven't been using the square brackets around the footnote super numbers because there's a danger of them ending up being reference-style MD links<sup>4</sup>. Like this<sup>[11]</sup> but not like this<sup>[12]</sup>.

[11]: http://markdown-here.com

Anyway, maybe this will help you and maybe it won't. It's probably more hassle than you're happy with. I'll include the raw version of this email below so that you can see it.

1. Gratuitous link to info about the `<sup>` tag: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/sup
2. [MD cheatsheet entry for lists](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet#wiki-lists)
3. [List of HTML entities](http://www.w3schools.com/tags/ref_symbols.asp)
4. https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet#links

[adam-p]

Refer to the following Marked issues/PRs:
markedjs/marked#27
markedjs/marked#431
markedjs/marked#351

[JustAShoeMaker]

There don't seem to be whole lotta requests for it, but I'll add my vote for this,

Really could have used it this morning.