Feature: click to pronounce

**Which module(s) and week(s) does this change affect?**
Module(s): all
Week(s): all

**What is the work that needs to be done?**

1. Create an unobtrusive speech synthesis vanilla web component
2. Add keyboard shortcut to speak selected

**Why is this work important to do?**

1. The majority of CYFers are reading in a second language and want pronunciation guides to help them with specific terms they won't hear otherwise.
2. Some CYFers prefer all spoken content over text

**Additional context**

Mathigon have a subtle click to read out loud button and this seems like a good thing to have on a paragraph level.
https://mathigon.org/course/codes/introduction

**Who might need to know about this change?**