DOC - Add alembic example for postgres in docker (#610)

conda-store-server/conda_store_server/alembic.ini

@@ -4,6 +4,9 @@
 script_location = {alembic_dir}
 sqlalchemy.url = {db_url}
 
+# script_location = alembic
+# sqlalchemy.url = postgresql+psycopg2://postgres:password@localhost:5432/conda-store
+
 # template used to generate migration files
 # file_template = %%(rev)s_%%(slug)s
 

docs/contributing.md

@@ -590,6 +590,12 @@ The procedure to modify the database is the following :
 - First, modify [the ORM Model](https://github.com/conda-incubator/conda-store/blob/main/conda-store-server/conda_store_server/orm.py) according to the changes you want to make
 - edit the file `conda-store-server/alembic.ini` and replace the value for entry `sqlalchemy.url` to match the connection URL of your database.
 
+For example (when postgres was started via docker-compose):
+```
+script_location = alembic
+sqlalchemy.url = postgresql+psycopg2://postgres:password@localhost:5432/conda-store
+```
+
 - in your command line, run the following :
 
 ```sh