add readme

README.md

@@ -1,3 +1,40 @@
 # sshenc.sh
+> bash script to encrypt data using a users ssh public key.
 
-Please see [https://sshenc.sh/](https://sshenc.sh/) (or the index.html file in this repository) for instructions.
+If you received a message from someone that was encrypted with this script, you can decrypt it with your ssh private key using the following command without installing anything:
+```
+bash <(curl -s https://sshenc.sh/sshenc.sh) -s ~/.ssh/id_rsa < file-containing-the-encrypted-text.txt
+```
+sshenc.sh uses openssl under the hood, so you need to have that installed in yout path to make it work.
+
+## Install
+```
+wget https://sshenc.sh/sshenc.sh
+chmod +x sshenc.sh
+```
+
+## Examples
+
+### encrypt a file using your own ssh public key
+```
+sshenc.sh -p ~/.ssh/id_rsa.pub < plain-text-file.txt > encrypted.txt
+```
+
+### encrypt a file using multiple recipients (broadcast encryption)
+```
+sshenc.sh -p ~/.ssh/id_rsa.pub -p id_rsa-alice.pub -p id_rsa-bob.pub < plain-text-file.txt > encrypted.txt
+```
+
+### encrypt a file using the public key of a github user
+```
+sshenc.sh -p <(curl -sf "https://github.com/S2-.keys" | grep ssh-rsa | tail -n1) < plain-text-file.txt
+```
+this line fetches the first public key for the github user S2- and encrypts the file plain-text-file.txt using this key.
+
+### dedecrypt a file
+```
+sshenc.sh -s ~/.ssh/id_rsa < encrypted.txt
+```
+
+## License
+[MIT](https://opensource.org/licenses/MIT)