Docs on `How to Upgrade`

[zachleat]

Surfaced here 11ty/buildawesome#361 (comment) by @kleinfreund

[zachleat]

This repository is now using lodash style issue management for documentation requests. This means documentation issues will now be closed instead of leaving them open.

View the documentation queue backlog here. Don’t forget to upvote the top comment with 👍!

[kleinfreund]

@zachleat I’d much rather have a few short lines in the actual readme document in the repository. That’s just sometimes the page people (including me) end up on. For example, I often navigate to pages by entering a string like ele into the address bar and let my browser suggest me the page I most often visit. For ele, that’s https://github.com/11ty/eleventy.

So I’d like to see something like this in the readme:

Installation & update

npm install -g @11ty/eleventy

---

Basically, the starting lines of the Getting Started document.

[zachleat]

Upgrade helper shipped here https://www.11ty.dev/docs/plugins/upgrade-help/