docs: Include info about UID in docs

README.md

@@ -116,8 +116,11 @@ docker run -p 4567:4567 \
     -d chhoto-url:latest
 ```
 
-You can also set the redirect method to Permanent 308 (default) or Temporary 307 by setting
-the `redirect_method` variable to `TEMPORARY` or `PERMANENT` (it's matched exactly).
+You can set the redirect method to Permanent 308 (default) or Temporary 307 by setting
+the `redirect_method` variable to `TEMPORARY` or `PERMANENT` (it's matched exactly). By
+default, the auto-generated links are adjective-name pairs. You can use UIDs by setting
+the `slug_style` variable to `UID`. You can also set the length of those slug by setting
+the `slug_length` variable. It defaults to 8, and a minimum of 4 is supported.
 
 ## Disable authentication
 If you do not define a password environment variable when starting the docker image, authentication

compose.yaml

@@ -21,6 +21,13 @@ services:
             # Pass the redirect method, if needed TEMPORARY and PERMANENT
             # are accepted values, defaults to PERMANENT
             # - redirect_method=TEMPORARY
+            
+            # By default, the auto-generated pairs are adjective-name pairs
+            # If you want UIDs, please change slug_style to UID
+            # Supported values for slug_style are "pair" and "UID"
+            # The length is 8 by default, and a minimum of 4 is allowed
+            # - slug_style=pair
+            # - slug_length=8
         volumes:
             - db:/urls.sqlite
         networks: