Merge branch 'un_peu_de_doc_pour_pablo' into 'main'

Doc: ajout de doc pour Pablo

See merge request !3

README.md

@@ -28,6 +28,64 @@ theia_dumper publish /data/stac/collection.json       # Publish collection
 theia_dumper publish /data/stac/item_collection.json  # Publish item collection
 ```
 
+## Usage
+
+### Prerequisites
+
+The user must be allowed to push files and metadata into the spatial data infrastructure:
+
+- Files
+- STAC objects
+
+In order to ask the permission to do so, the user must perform a [merge request](https://docs.gitlab.com/ee/user/project/merge_requests/) 
+in [this repository](https://gitlab.irstea.fr/umr-tetis/cdos-ops), modifying two files 
+(here we assure that the user is named `jacques.chirac`!):
+
+- `buckets.json`: add a bucket and a path prefix where the files will be uploaded,
+
+Typically, one should use the `gdc-sm1` bucket, with a path prefix which is not already 
+used, e.g.:
+
+```json
+    ...,
+    "jacques.chirac": [
+      {
+        "s3_endpoint": "s3-data.meso.umontpellier.fr",
+        "buckets": [
+            "sm1-gdc/collection1234",
+            "sm1-gdc/collection4567", 
+            "sm1-gdc/collection_chirac/1", 
+            "sm1-gdc/collection_chirac/2"
+        ]
+      }
+    ],
+    ...
+```
+
+- `transations_rules.json`: itemize the STAC collections IDs that will be created and modified.
+
+```json
+    ...,
+    "jacques.chirac": [
+        "collectionXYZ", 
+        "collection123"
+    ],
+    ...
+```
+
+Note that collections IDs and buckets/paths prefixes are completely independant.
+
+### CLI
+
+In the `theia-dumper` CLI, the `--storage_bucket` argument concatenates the actual bucket and 
+the path prefix.
+
+For instance if jacques wants to upload a collection in `sm1-gdc/collection1234`, he will have to call:
+
+```commandLine
+theia-dumper /home/jacques/stac/collection.json --storage_bucket sm1-gdc/collection1234
+```
+
 ## Contact
 
 remi cresson @ inrae