Explain the database conda recipe difference

templates/README.md

@@ -261,6 +261,21 @@ them. The test-time dependencies are listed in `test-requirements.txt`. If this
 file does not exist, just remove the line that says `<TEST_DEPS>`.
 
 
+### Database packages and packages with extra data
+
+Sometimes databases or other packages require an extra download command after
+installation. If this extra data is downloaded from Idiap severs, you can
+include this data in the conda package itself to avoid downloading it two
+times. If the data is supposed to be downloaded from somewhere other than Idiap
+servers, do not include it in its conda package. For example, the database
+packages typically require this download command to be added in the
+`build:script` section:
+
+```yaml
+    - python setup.py install --single-version-externally-managed --record record.txt # this line is already in the recipe. Do not add.
+    - bob_dbmanage.py {{ name.replace('bob.db.', '') }} download --missing
+```
+
 ## 2. Licensing
 
 Verify if the license of your package satisfies what is written on our