Docusaurus-ify 1.19 (#26053)

See https://github.com/go-gitea/gitea/pull/26051

---------

Signed-off-by: jolheiser <john.olheiser@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
(cherry picked from commit 8c771c8b91)

docs/content/doc/administration/environment-variables.en-us.md

@@ -1,63 +0,0 @@
----
-date: "2017-04-08T11:34:00+02:00"
-title: "Environment variables"
-slug: "environment-variables"
-weight: 10
-toc: false
-draft: false
-menu:
-  sidebar:
-    parent: "administration"
-    name: "Environment variables"
-    weight: 10
-    identifier: "environment-variables"
----
-
-# Environment variables
-
-**Table of Contents**
-
-{{< toc >}}
-
-This is an inventory of Gitea environment variables. They change Gitea behaviour.
-
-Initialize them before Gitea command to be effective, for example:
-
-```sh
-GITEA_CUSTOM=/home/gitea/custom ./gitea web
-```
-
-## From Go language
-
-As Gitea is written in Go, it uses some Go variables, such as:
-
-- `GOOS`
-- `GOARCH`
-- [`GOPATH`](https://golang.org/cmd/go/#hdr-GOPATH_environment_variable)
-
-For documentation about each of the variables available, refer to the
-[official Go documentation](https://golang.org/cmd/go/#hdr-Environment_variables).
-
-## Gitea files
-
-- `GITEA_WORK_DIR`: Absolute path of working directory.
-- `GITEA_CUSTOM`: Gitea uses `GITEA_WORK_DIR`/custom folder by default. Use this variable
-  to change _custom_ directory.
-- `GOGS_WORK_DIR`: Deprecated, use `GITEA_WORK_DIR`
-- `GOGS_CUSTOM`: Deprecated, use `GITEA_CUSTOM`
-
-## Operating system specifics
-
-- `USER`: System user that Gitea will run as. Used for some repository access strings.
-- `USERNAME`: if no `USER` found, Gitea will use `USERNAME`
-- `HOME`: User home directory path. The `USERPROFILE` environment variable is used in Windows.
-
-### Only on Windows
-
-- `USERPROFILE`: User home directory path. If empty, uses `HOMEDRIVE` + `HOMEPATH`
-- `HOMEDRIVE`: Main drive path used to access the home directory (C:)
-- `HOMEPATH`: Home relative path in the given home drive path
-
-## Miscellaneous
-
-- `SKIP_MINWINSVC`: If set to 1, do not run as a service on Windows.