fill out configuration and building sections of readme

readme.md

@@ -16,3 +16,32 @@ Only configured admin user can add, edit or delete notes. To add a note, you nee
 noted.properties configuration file. You can specify multiple user ids separated by `,`. You can use add-note command to
 add a note, edit-note to edit a note, delete-note to delete a note. Those commands are only available in the direct
 message channel with the bot.
+
+### Configuration
+
+```properties
+DISCORD_TOKEN=your_bot_token_here
+ADMIN_USER_ID=your_user_id_here,another_user_id_here
+COMMAND=note
+```
+
+#### DISCORD_TOKEN
+This is the token that you get when you create a bot in the [discord developer portal](https://discord.com/developers).
+
+#### ADMIN_USER_ID
+This is the user id of the admin user. You can get your user id by enabling developer mode in discord and right-clicking
+on your user in the user list. You can specify multiple user ids separated by `,`.
+
+#### COMMAND
+This is the command that users will use to retrieve a note. You can change this to any command you want except existing
+admin commands. If you set this to any admin command, default `note` will be used.
+
+### Building
+
+To build the app, you need to have maven installed. Run the following command to build the app:
+
+```shell
+mvn clean package
+```
+
+This will create a jar file in the /target directory. You can run the jar using java 21 or higher: