fix: update env var names in docker-compose with the latest names

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ### Changed
 
+-   2023-10-18: Environment variable names have changed, please see
+    [CONFIGURATION.md](docs/CONFIGURATION.md) for the names of environment
+    variables.
 -   ([`7d0e4c6`](https://github.com/mCaptcha/mCaptcha/commit/7d0e4c6be4b0769921cda7681858ebe16ec9a07b)) Add `secret` parameter to token verification request payload(`/api/v1/pow/siteverify`) to mitigate a security issue that @gusted found:
     > ...A malicious user could grab the sitekey
     > and use that sitekey with mcaptcha to use it for their own server.

docker-compose.yml

@@ -11,8 +11,8 @@ services:
       - 7000:7000
     environment:
       DATABASE_URL: postgres://postgres:password@mcaptcha_postgres:5432/postgres # set password at placeholder
-      MCAPTCHA_REDIS_URL: redis://mcaptcha_redis/
-      RUST_LOG: debug
+      MCAPTCHA_redis_URL: "redis://mcaptcha_redis/"
+      RUST_LOG: "debug"
       PORT: 7000
     depends_on:
       - mcaptcha_postgres