Archiving Godot 2.1.4 documentation

Hey folks!

With Godot 4.0 just around the corner, it occurred to me that they might soon remove the docs for 2.1.

For anyone unfamiliar, it’s known that Godot can export to Ouya up to version 2.1.4. Fortunately, the builds for this version are still hosted here but the docs are at risk of being taken down.

As such, I wondered if it was possible to archive the documentation in it’s 2.1 release state :thinking:

Here’s how to do it on an Ubuntu machine:

## Get sphinx and the readthedocs theme
sudo apt install python3-pip
pip3 install sphinx sphinx_rtd_theme

## Clone the docs repo
git clone --recursive

## Go inside the repo
cd godot-docs

## Switch to the 2.1 branch
git checkout --force origin/2.1

make html

The offline HTML build will then be available at _build/html/index.html.