chore(docker): improve compose configuration

Set expected environment variables using host one.

docker-compose.yml

@@ -1,13 +1,20 @@
 ---
 services:
   nvim:
-    build: .
+    build:
+      context: .
+      args:
+        GIT_USER_EMAIL: ${NVIM_GIT_USER_EMAIL:-nobody@example.com}
+        GIT_USER_NAME: ${NVIM_GIT_USER_NAME:-noboby}
     image: 'joaodubas/nvim:${NVIM_TAG:-latest}'
     init: true
     restart: unless-stopped
     hostname: local
     entrypoint: sleep
     command: infinity
+    environment:
+      ANTHROPIC_API_KEY: ${NVIM_ANTHROPIC_API_KEY:-no-api}
+      GH_TOKEN: ${NVIM_GH_TOKEN:-no-token}
     volumes:
       - './config/atuin:/home/coder/.config/atuin'
       - './config/git:/home/coder/.config/git'