add docker tasks

docker/Taskfile.docker.yml

@@ -0,0 +1,23 @@
+version: '3'
+
+tasks:
+  build:
+    desc: Build the Docker image
+    cmds:
+      - docker build -t q3rcon-proxy -f docker/Dockerfile .
+    dir: .
+
+  login:
+    desc: Login to Github Container Registry
+    cmds:
+      - docker login ghcr.io -u onyx-and-iris --password-stdin <<< {{.GHCR_TOKEN}}
+    internal: true
+
+  push:
+    desc: Push the Docker image to Github Container Registry
+    deps:
+      - task: build
+      - task: login
+    cmds:
+      - docker tag q3rcon-proxy ghcr.io/onyx-and-iris/q3rcon-proxy:latest
+      - docker push ghcr.io/onyx-and-iris/q3rcon-proxy:latest