Update README.md (#276)

### Summary

This PR fixes a small typo in the documentation:
- Changed "adress" to "address" in README.md.

Author: iliyami

README.md

@@ -8,11 +8,11 @@ Tests: [![Build Status](https://api.travis-ci.org/yellowtree/geoip-detect.svg?br
 
 * **Donate Link:** https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=BSYUZHS8FH3CL
 
-Provides geographic information detected by an IP adress.
+Provides geographic information detected by an IP address.
 
 ## Description ##
 
-Provides geographic information detected by an IP adress. This can be used in themes or other plugins, as a shortcode, or via CSS body classes. The city & country names are translated in different languages ([supported languages](https://dev.maxmind.com/geoip/geoip2/web-services/#Languages-8)).
+Provides geographic information detected by an IP address. This can be used in themes or other plugins, as a shortcode, or via CSS body classes. The city & country names are translated in different languages ([supported languages](https://dev.maxmind.com/geoip/geoip2/web-services/#Languages-8)).
 
 = Features: =
 
@@ -28,7 +28,7 @@ Provides geographic information detected by an IP adress. This can be used in th
   * `geoip_detect2_get_info_from_ip($ip, $locales = array('en'), $options = array())`: Lookup Geo-Information of the specified IP
   * `geoip_detect2_get_info_from_current_ip($locales = array('en'), $options = array())`: Lookup Geo-Information of the current website user
   * `geoip_detect2_get_current_source_description(...)`: Return a human-readable label of the currently chosen source.
-  * `geoip_detect2_get_external_ip_adress()`: Fetch the internet adress of the webserver
+  * `geoip_detect2_get_external_ip_adress()`: Fetch the internet address of the webserver
   * `geoip_detect2_get_client_ip()`: Get client IP (even if it is behind a reverse proxy)
 * For the property names, see the results of a specific IP in the wordpress backend (under *Tools > Geolocation IP Detection*).
 * You can include these properties into your posts and pages by using the shortcode `[geoip_detect2 property="country.name" default="(country could not be detected)" lang="en"]` (where 'country.name' can be one of the other property names as well, and 'default' and 'lang' are optional).