add README

README.md

@@ -1,2 +1,34 @@
 # captive-netns-helper
 
+This is a program for Linux that helps you bypass VPN rules in routing table and
+custom system DNS resolver and access internet directly via physical interface.
+It was written for accessing Wi-Fi captive portals. It comes with a wrapper script
+to be easier to use.
+
+Read more [here](https://ch1p.io/gentoo-wireguard-custom-resolver-captive-portal/).
+
+## Installation
+
+```
+git clone https://github.com/gch1p/captive-netns-helper
+cd captive-netns-helper
+mkdir build
+cd build
+cmake ..
+make -j4
+sudo make install
+```
+
+## Usage
+```
+captive-portal.sh PROGRAM [ARGUMENTS]
+```
+
+For example:
+```
+captive-portal.sh curl -v https://captive.apple.com
+```
+
+## License
+
+MIT