Explain installation, usage and made some remarks

README.md

@@ -13,6 +13,67 @@ Packaging informations :
 - https://packaging.python.org/en/latest/tutorials/packaging-projects/
 - https://choosealicense.com/
 
+## Remark
+
+The data files do not need to be packaged, just place them where the data
+folder is installed.
+
+## Build and install the package
+
+```shell
+$ flit build
+$ pip install dist/import_resources_example-0.0.1-py3-none-any.whl
+```
+
+WARNING : The package is installed in the virtual environment, so the data
+files must be placed there which is not a very pleasant location.
+
+```shell
+$ tree .venv/lib/python3.10/site-packages/import_resources_example
+├── data
+│   └── __init__.py
+├── get_oms_data.py
+├── get_population_info.py
+└── __init__.py
+```
+
+When installing the package in development mode with `pip install -e .`, the
+data folder is in the clone repository.
+
+## Usage
+
+Install the package and try to execute the functions.
+
+```ipython
+In [1]: from import_resources_example import get_population_info
+
+In [2]: get_population_info.extract_population_general_info()
+{'AUKUS': {'Time': '1950', 'PopTotal': '206513.782', 'PopDensity': '12.096'},
+ 'African Group': {'Time': '1950',
+  'PopTotal': '227261.208',
+  'PopDensity': '7.761'},
+ 'African Union': {'Time': '1950',
+  'PopTotal': '227274.19',
+  'PopDensity': '7.692'},
+
+In [3]: from import_resources_example import get_oms_data
+
+In [4]: get_oms_data.get_oms_data()
+Out[4]: 
+[{'TrialID': 'NCT00173563',
+  'Public-title': 'Induction of Cytokines in Human Monocytes by SARS-CoV in Adults and Children',
+  'Date-registration': '12/09/2005',
+  'Source-Register': 'ClinicalTrials.gov',
+  'Recruitment-Status': 'Recruiting',
+  'Study type': 'Observational'},
+ {'TrialID': 'NCT00523276',
+  'Public-title': 'SARS Survivor Evaluations',
+  'Date-registration': '30/08/2007',
+  'Source-Register': 'ClinicalTrials.gov',
+  'Recruitment-Status': 'Not recruiting',
+  'Study type': 'Observational'},
+```
+
 ## Troubleshooting
 
 If we have untracked data files in the package tree, flist refuses to build the