document installation

README.md

@@ -19,3 +19,26 @@ When you create a password URL, PassED firstly encrypts the password in your bro
 When someone views the password, PassED looks at the URL. It knows the password ID, AES Key and IV. It reaches out to the server, asks for a password with the ID from the URL, and then decrypts it with the AES Key and IV.
 
 This model ensures that a malicous host can not read the passwords.
+
+## Installation
+Installation is done with docker compose.
+```yaml
+services:
+  "passed":
+    build: "https://git.1e99.eu/1e99/passed.git"
+    volumes:
+      - "./passed:/etc/passed"
+    environment:
+      - "PASSED_STORE_TYPE=dir"
+      - "PASSED_STORE_DIR_PATH=/etc/passed"
+    ports:
+      - "3000:3000"
+```
+
+## Configuration
+Configuration is done with environment variables.
+- `PASSED_ADDRESS`: Specifies the address that PassED should listen on, defaults to `:3000`
+- `PASSED_STORE_TYPE`: Specify which store to use to save passwords, defaults to `ram`:
+  - `ram`: Stores all passwords in RAM, they are lost on restart
+  - `dir`: Stores all passwords in a directory. Requires `PASSED_STORE_DIR_PATH` to be set to the directory, defaults to `passwords`. PassED will not create the directory.
+- `STORE_CLEAR_EXPIRED_INTERVAL`: Specifies the delay in seconds to wait between clearing expired passwords, defaults to `30`.