Migrate plone.exportimport documentation (#1842)

* Migrate plone.exportimport documentation

* Update docs/admin-guide/import-export.md

Co-authored-by: Maurits van Rees <maurits@vanrees.org>

---------

Co-authored-by: Maurits van Rees <maurits@vanrees.org>

Author: stevepiercy

docs/admin-guide/import-export.md

@@ -0,0 +1,113 @@
+---
+myst:
+  html_meta:
+    "description": "Export and import Plone site data with plone.exportimport"
+    "property=og:description": "Export and import Plone site data with plone.exportimport"
+    "property=og:title": "Export and import Plone site data with plone.exportimport"
+    "keywords": "Plone 6, plone.exportimport, export, import, site, data, Content, Principals, Relations, Translations, Discussions, Redirects"
+---
+
+(exportimport)=
+
+# Export and import site data
+
+The `plone.exportimport` package provides support to export and import all kinds of data from and to Plone sites using an intermediate JSON format.
+
+Most features use {doc}`plone.restapi <../plone.restapi/docs/source/index>` to serialize and deserialize data.
+
+
+## Command line utilities
+
+This package provides two command line utilities, `plone-exporter` and `plone-importer`.
+
+### `plone-exporter`
+
+Export content from a Plone site to a directory in the file system.
+You can call `plone-exporter` as shown.
+
+```shell
+plone-exporter [--include-revisions] <path-to-zopeconf> <site-id> <path-to-export-data>
+```
+
+The following command shows typical usage.
+
+```shell
+plone-exporter instance/etc/zope.conf Plone /tmp/plone_data/
+```
+
+By default, the revisions history (older versions of each content item) are not exported.
+If you do want them, add `--include-revisions` on the command line.
+
+
+### `plone-importer`
+
+Import content from a file system directory into an existing Plone site.
+
+You can call `plone-importer` as shown.
+
+```shell
+plone-importer <path-to-zopeconf> <site-id> <path-to-import-data>
+```
+
+The following command shows typical usage.
+
+```shell
+plone-importer instance/etc/zope.conf Plone /tmp/plone_data/
+```
+
+
+## Supported data
+
+-   Content (Dexterity content items)
+    -   Ordering
+    -   Local roles
+    -   Versions (when using the `--include-revisions` command line option)
+    -   Default pages
+-   Principals (members and groups)
+-   Relations (relationships between content items)
+-   Translations (translation groups)
+-   Discussions (content comments)
+-   Redirects (redirect information)
+
+
+## Exported data structure
+
+Some goals of the new data structure are to:
+
+-   support diff of exported data, and
+-   have blob files near the content item that uses it.
+
+After exporting content, at the top level directory, the following objects exist.
+
+| Name | Description |
+| --- | --- |
+| `content` | Directory containing content item information exported from the site |
+| `discussions.json` | JSON File with discussions (comments) exported from the site |
+| `principals.json` | JSON File with members and groups exported from the site |
+| `redirects.json` | JSON File with redirect information exported from the site |
+| `relations.json` |  JSON File with content relations exported from the site  |
+| `translations.json` | JSON File with translation groups exported from the site  |
+
+
+### Content directory structure
+
+The {file}`content` directory contains all content items exported from the site.
+Each content item has its own subdirectory, named with the UID of the content, including the serialized data and all blob files related to this content.
+
+One special case is the directory for the `Plone Site` object, which is named `plone_site_root`.
+
+| Name | Description |
+| --- | --- |
+| `content/__metadata__.json` | JSON File with metadata information about the exported content |
+| `content/<content uid>` | Directory with serialization for a content item |
+| `content/plone_site_root` | Directory with serialization for the Plone Site Root |
+
+
+#### Content item directory structure
+
+Consider a File content item with UID `3e0dd7c4b2714eafa1d6fc6a1493f953` and a PDF file named {file}`plone.pdf` (added in the `file` field), the exported directory will have the following structure.
+
+| Name | Description |
+| --- | --- |
+| `content/3e0dd7c4b2714eafa1d6fc6a1493f953/data.json` | JSON File with serialized representation of a content item |
+| `content/3e0dd7c4b2714eafa1d6fc6a1493f953/file/plone.pdf` | Blob file stored in the `file` field in the content item |

docs/admin-guide/index.md

@@ -32,6 +32,7 @@ run-plone
 add-site
 configure-zope
 add-ons
+import-export
 override-core
 /upgrade/index
 ```