Link emoji 🔗

Added 🔗 emoji for <a> tags in the poul.css template stylesheet.

This is a solution to the problem pointed out by many members and course participants of the bold style being too similar to the link style in the current POuL template for reveal.js.

This solution puts a 🔗 emoji in front of all <a> tags by default (originally an idea pioneered by @lero), this behavior can be overridden by applying the noemoji class to the tag in the following ways:

HTML:

<a href="https://example.com" class="noemoji">link</a>

Markdown:

[link](https://example.com) <!-- .element: class="noemoji" -->

In addition:

• the nolinkemoji can be used on any HTML element to avoid applying the link emoji to its child <a> tags
• the emoji class can be used on an <a> tag to force the visualization of the emoji in the previous scenario
• the emojisuper class can be used as an alternative emoji visualization in superscript and at the end of the link element
• the has-noemoji class should exclusively be applied to <a> tags that wrap around images and don't need the emoji, this is a workaround as we would want to perform this by default: issue #9 (closed)