New features and essential updates

Release notes:

• Adds .get_release_timestamp() static method to obtain the website timestamp (see the docs before use).
• Adds .as_dataframe() method to retrieve the data as a Pandas DataFrame object (see the docs before use).
• Adds comprehensive documentations.
• Development: Adds depandabot to ensure that all dependencies are kept up to date.
• Development: Adds new unit tests.
• Other minor improvements.