Add episode on releases and tags

[alexdewar]

Hi all,

Here's the first draft of my releases/tags section. Let me know if you have any suggestions!

Closes #7.

[alexdewar]

I looks really nice and it is easy to follow and understand. My only comment is that there are no proper exercises. You do encourage to code along and follow the commands you are running, but you don't stop, give them time to do their stuff and then check the results. Even though most tasks are simple, it will be worth to have them arranged as exercises.

Good suggestion. I've added two exercises, but nothing obvious presented itself to me for the other sections. Any ideas? @TinyMarsh?

[dalonsoa]

@dandavies99 , could you have a quick look at this lesson, and then we move on?

[dalonsoa]

And @TinyMarsh