chore: readme

README.md

@@ -14,7 +14,24 @@ The model of the Daya Bay experiment.
 The data is located in a [restricted repository](https://git.jinr.ru/dag-computing/dayabay-data-all), to enable it use:
 
 ```sh
+git lfs install --skip-repo # initialize the LFS (if needed)
 git clone git@git.jinr.ru:dag-computing/dayabay-data-all.git data
 ```
 
-It should be located in the `data/` folder.
+It should be located in the `data/` folder. Note that git LFS is used to store the data files. It should be initialized (once) if not used before.
+
+## Quick start
+
+The repository depends on a few submodules. To initialize them use:
+
+```sh
+git submodule sync
+git submodule update --init --recursive -- submodules/dag-flow
+git submodule update --init -- submodules/dagflow-reactornueosc submodules/dagflow-detector submodules/dagflow-statistics
+python3 -m pip install -r requirements.txt
+```
+
+this will:
+1. Synchronize submodules
+2. Check out the core submodule `dag-flow` recursively
+3. Check out the physics repositories