doc: add proper readme

README.md

@@ -1,3 +1,17 @@
-# wichteln
+# Wichteln
 
-A script that allows you to organise a secret santa game. 
+This is a smalls script that allows you to organise a secret santa game (or 
+»Wichteln« in German). It has the follwing arguments:
+
+- `-h` displays a help message
+- `-c FILE` or `--config FILE` specifies the location of the configuration file, which should contain all information needed to connect to an SMTP server. An example configuration file is given in `config.json`. It also defaults to `config.json`.
+- `-p FILE` or `--participants FILE` specifies the location of the file containing a list of participants. An example configuration file is given in `participants.json`. It also defaults to `participants.json`.
+
+## participants.json Format
+The `participants.json` file contains an array of objects. Each objects should specifiy the following three fields:
+
+- `name` The name of the participant
+- `mail` The email adress of the participant
+- `gender` This field is necessary, because this script has to send emails adressing each participant correctly and in german that depends on the gender of the recipient. However instead of just choosing a boolean value to represent gender, I chose to just store the actually needed information: the ending for the german word »Lieb(e|er|...)«. This allows for more then two genders and is in my opinion generally a little bit more elegant to use in this context.
+
+**Note:** This script was created in a german speaking context, if you want to adapt the emails that this script sends, change the text in lines 78 and 81-84.