Add Conda package registry (#22262)

This PR adds a [Conda](https://conda.io/) package registry.

docs/content/doc/packages/conda.en-us.md

@@ -0,0 +1,85 @@
+---
+date: "2022-12-28T00:00:00+00:00"
+title: "Conda Packages Repository"
+slug: "packages/conda"
+draft: false
+toc: false
+menu:
+  sidebar:
+    parent: "packages"
+    name: "Conda"
+    weight: 25
+    identifier: "conda"
+---
+
+# Conda Packages Repository
+
+Publish [Conda](https://docs.conda.io/en/latest/) packages for your user or organization.
+
+**Table of Contents**
+
+{{< toc >}}
+
+## Requirements
+
+To work with the Conda package registry, you need to use [conda](https://docs.conda.io/projects/conda/en/stable/user-guide/install/index.html).
+
+## Configuring the package registry
+
+To register the package registry and provide credentials, edit your `.condarc` file:
+
+```yaml
+channel_alias: https://gitea.example.com/api/packages/{owner}/conda
+channels:
+  - https://gitea.example.com/api/packages/{owner}/conda
+default_channels:
+  - https://gitea.example.com/api/packages/{owner}/conda
+```
+
+| Placeholder  | Description |
+| ------------ | ----------- |
+| `owner`      | The owner of the package. |
+
+See the [official documentation](https://conda.io/projects/conda/en/latest/user-guide/configuration/use-condarc.html) for explanations of the individual settings.
+
+If you need to provide credentials, you may embed them as part of the channel url (`https://user:password@gitea.example.com/...`).
+
+## Publish a package
+
+To publish a package, perform a HTTP PUT operation with the package content in the request body.
+
+```
+PUT https://gitea.example.com/api/packages/{owner}/conda/{channel}/{filename}
+```
+
+| Placeholder  | Description |
+| ------------ | ----------- |
+| `owner`      | The owner of the package. |
+| `channel`    | The [channel](https://conda.io/projects/conda/en/latest/user-guide/concepts/channels.html) of the package. (optional) |
+| `filename`   | The name of the file. |
+
+Example request using HTTP Basic authentication:
+
+```shell
+curl --user your_username:your_password_or_token \
+     --upload-file path/to/package-1.0.conda \
+     https://gitea.example.com/api/packages/testuser/conda/package-1.0.conda
+```
+
+You cannot publish a package if a package of the same name and version already exists. You must delete the existing package first.
+
+## Install a package
+
+To install a package from the package registry, execute one of the following commands:
+
+```shell
+conda install {package_name}
+conda install {package_name}={package_version}
+conda install -c {channel} {package_name}
+```
+
+| Parameter         | Description |
+| ----------------- | ----------- |
+| `package_name`    | The package name. |
+| `package_version` | The package version. |
+| `channel`         | The channel of the package. (optional) |