Anchor link in chapter 10 not working

[tillydray]

~There's a link~ There are (at least) 2 links in chapter 10, to the

• folds section in Higher order functions, and
• composition section also in Higher order functions

~the anchor link is both~ which are malformed. The current anchor links ~is~ are

• https://learnyouanelm.github.io/pages/06-higher-order-functions/#folds
• https://learnyouanelm.github.io/pages/06-higher-order-functions#composition

I tried several permutations but couldn't get it to work, otherwise I'd submit a PR.

EDIT: added the second malformed anchor link after I discovered it.

[ebenpack]

Nice catches. These are both been fixed now. The markdown generated section headings also automatically generate an ID, so this

Function composition
--------------------

In mathematics, function composition is defined like this:

Generates this markup with the following section heading:

<h2 id="function-composition">Function composition</h2>

<p>In mathematics, function composition is defined like this:<p>

And you can link to this like:

[point-free style](06-higher-order-functions#function-composition)

The other link also had a trailing slash.