Revert "Updated HTML docs."

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docs/source/Setup/Installation-Upgrade.md

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+# Upgrading an existing installation
+
+## Evennia v0.9.5 to 1.0
+
+Prior to 1.0, all Evennia installs were [Git-installs](./Installation-Git.md). These instructions
+assume that you have a cloned `evennia` repo and use a virtualenv (best practices).
+
+- Make sure to stop Evennia 0.9.5 entirely with `evennia stop`.
+- `deactivate` to leave your active virtualenv.
+- Make a _backup_ of your entire `mygame` folder, just to be sure!
+- Delete the old `evenv` folder, or rename it (in case you want to keep using 0.9.5 for a while).
+- Install Python 3.10 (recommended) or 3.9. Follow the [Git-installation](./Installation-Git.md) for your OS if needed.
+- If using virtualenv, make a _new_ one with `python3.10 -m venv evenv`, then activate with `source evenv/bin/activate`
+  (linux/mac) or `\evenv\Script\activate` (windows)
+- `cd` into your `evennia/` folder (you want to see the `docs/`, `bin/` directories as well as a nested `evennia/` folder)
+- **Prior to 1.0 release only** - do `git checkout develop` to switch to the develop branch. After release, this will
+  be found on the default master branch.
+- `git pull`
+- `pip install -e .`
+- If you want the optional extra libs, do `pip install -r requirements_extra.txt`.
+- Test that you can run the `evennia` command.
+
+If you don't have anything you want to keep in your existing game dir, you can just start a new onew
+using the normal [install instructions](./Installation.md). If you want to keep/convert your existing
+game dir, continue below.
+
+- First, make a backup of your exising game dir! If you use version control, make sure to commit your current state.
+- `cd` to your existing 0.9.5-based game folder (like `mygame`.)
+- If you have changed `mygame/web`, _rename_ the folder to `web_0.9.5`. If you didn't change anything (or don't have
+anything you want to keep), you can _delete_ it entirely.
+- Copy `evennia/evennia/game_template/web` to `mygame/` (e.g. using `cp -Rf` or a file manager). This new `web` folder
+replaces the old one and has a very different structure.
+- It's possible you need to replace/comment out import and calls to the deprecated
+[`django.conf.urls`](https://docs.djangoproject.com/en/3.2/ref/urls/#url). The new way to call it is
+[available here](https://docs.djangoproject.com/en/4.0/ref/urls/#django.urls.re_path).
+- Run `evennia migrate`
+- Run `evennia start`
+
+If you made extensive work in your game dir, you may well find that you need to do some (hopefully minor)
+changes to your code before it will start with Evennia 1.0. Some important points:
+
+- The `evennia/contrib/` folder changed structure - there are now categorized sub-folders, so you have to update
+your imports.
+- Any `web` changes need to be moved back from your backup into the new structure of `web/` manually.
+- See the [Evennia 1.0 Changelog](../Coding/Changelog.md) for all changes.