Add documentation to IpregistryConfig

This closes #39

Author: laurentpellegrino

ipregistry/core.py

@@ -99,9 +99,25 @@ def _is_api_error(self, data):
 
 class IpregistryConfig:
     def __init__(self, key, base_url="https://api.ipregistry.co", timeout=15):
+        """
+        Initialize the IpregistryConfig instance.
+
+        Parameters:
+        key (str): The API key for accessing the Ipregistry service.
+        base_url (str): The base URL for the Ipregistry API. Defaults to "https://api.ipregistry.co".
+                        There also exists a European Union (EU) base URL "https://eu.api.ipregistry.co"
+                        that can be used to ensure requests are handled by nodes hosted in the EU only.
+        timeout (int): The timeout duration (in seconds) for API requests. Defaults to 15 seconds.
+        """
         self.api_key = key
         self.base_url = base_url
         self.timeout = timeout
 
     def __str__(self):
-         return "api_key={}, base_url={}, timeout={}".format(self.api_key, self.base_url, self.timeout)
+        """
+        Return a string representation of the IpregistryConfig instance.
+
+        Returns:
+        str: A string containing the API key, base URL, and timeout value.
+        """
+        return "api_key={}, base_url={}, timeout={}".format(self.api_key, self.base_url, self.timeout)