remove rootless dockerfile, updatedate entrypoint, update docker compose

Removed the rootless dockerfile as upon further investigation into how a `rootless` container works, the entrypoint that has been written fully accomodates that

to reflect this the compose file has had the rootless config removed from it as it is no longer needed to test a seperate container image,

added a debug echo function `decho` to the entrypoint, when `DEBUG=true` it will print "[entrypoint] message content"

added a 10 second wait to the entrypoint to allow other services such as docker-in-docker and forgejo to finish launching before the runner is launched, this is bypassable by `SKIP_WAIT=true`

applied several modifications requested by viceice,

examples/docker-compose/compose-forgejo-and-runner.yml

@@ -7,7 +7,7 @@
 #   openssl rand -hex 20
 #
 # Replace all occurences of {SHARED_SECRET} below with the output.
-# 
+#
 # NOTE: a token obtained from the Forgejo web interface cannot be used
 #       as a shared secret.
 #
@@ -23,20 +23,19 @@ volumes:
 services:
   docker-in-docker:
     image: code.forgejo.org/oci/docker:dind
-    container_name: docker # needed for docker internal DNS resolution
-    hostname: docker  # Must set hostname as TLS certificates are only valid for docker or localhost
+    # container_name: docker # Must set container_name to docker for both internal DNS and TLS to work
+    hostname: docker
     privileged: true
     networks:
       - forgejo
     environment:
-      DOCKER_TLS_CERTDIR: "" # set to "certs" to use the TLS certificates, also update existing runner configs to use port 2376
-      DOCKER_HOST: docker-in-docker
+      DOCKER_TLS_CERTDIR: "/certs" # set to "" to disable the use of TLS, also manually update existing runner configs to use port 2375
     volumes:
       - docker_certs:/certs
 
   forgejo:
     image: codeberg.org/forgejo/forgejo:1.21
-    container_name: forgejo
+    hostname: forgejo
     networks:
       - forgejo
     volumes:
@@ -47,20 +46,21 @@ services:
       bash -c '
       /bin/s6-svscan /etc/s6 &
       sleep 10 ;
+      su -c "forgejo admin user create --admin --username root --password examplepassword --email root@example.com" git ;
       su -c "forgejo forgejo-cli actions register --secret {SHARED_SECRET}" git ;
       sleep infinity
       '
 
+  # all values that have defaults listed are optional
+  # only FORGEJO_SECRET or RUNNER_TOKEN is required
+  # FORGEJO_URL is required if forgejo is in this compose file or docker network
   forgejo-runner:
     ## TODO: Update image to the the release
     ## made from this PR: https://code.forgejo.org/forgejo/runner/pulls/283
-    
-    # image: code.forgejo.org/forgejo/runner:3.4.1 
-    build:
-      context: ../../
-      dockerfile: Dockerfile
-    container_name: forgejo-runner
-    # user: "1000" # set to run rootless, overrides RUNNER_USER
+
+    # image: code.forgejo.org/forgejo/runner:3.4.1
+    build: ../../
+    # user: "1000" # set to run rootless, overrides RUNNER_USER and disables automatic file ownership
     volumes:
       - ./forgejo-runner:/data
       - docker_certs:/certs
@@ -70,39 +70,19 @@ services:
       - docker-in-docker
       - forgejo
     environment:
-      CONFIG_FILE: config.yml      # defaults to /data/config.yml
+      CONFIG_FILE: config.yml # defaults to /data/config.yml
 
-      FORGEJO_URL: ${FORGEJO_URL}  # defaults to http://forgejo:3000
-      FORGEJO_SECRET: "{SHARED_SECRET}" # shared secret, must match Forgejo's
+      DOCKER_HOST: "docker" # defaults to docker
+      DOCKER_TLS_CERTDIR: "/certs/client" # defaults to /certs/client
+      DOCKER_TLS_VERIFY: "1" # defaults to 0, set to 1 to enable TLS
 
-      RUNNER_FILE:  runner.json    # defaults to /data/runner.json
-      RUNNER_NAME:  forgejo-runner # defaults to forgejo-runner, used for registration
+      FORGEJO_URL: ${FORGEJO_URL} # defaults to http://forgejo:3000
+      FORGEJO_SECRET: "{SHARED_SECRET}" # shared secret, must match Forgejo's, overrides RUNNER_TOKEN
+
+      RUNNER_FILE: .runner # defaults to /data/runner.json
+      RUNNER_NAME: forgejo-runner # defaults to forgejo-runner, used for registration
       RUNNER_TOKEN: "${RUNNER_TOKEN}"
-      RUNNER_USER:  1000           # defaults to 1000
+      RUNNER_USER: 1000 # defaults to 1000, allows for automatic file ownership
 
-  forgejo-runner-rootless:
-    ## TODO: Update image to the the release
-    ## made from this PR: https://code.forgejo.org/forgejo/runner/pulls/283
-    
-    # image: code.forgejo.org/forgejo/runner:3.4.1 
-    build:
-      context: ../../
-      dockerfile: Dockerfile.rootless
-    container_name: forgejo-runner-rootless
-    volumes:
-      - ./forgejo-runner:/data
-      - docker_certs:/certs
-    networks:
-      - forgejo
-    depends_on:
-      - docker-in-docker
-      - forgejo
-    environment:
-      CONFIG_FILE: config-rootless.yml      # defaults to /data/config.yml
-
-      FORGEJO_URL: ${FORGEJO_URL}  # defaults to http://forgejo:3000
-      FORGEJO_SECRET: "{SHARED_SECRET}" # shared secret, must match Forgejo's
-
-      RUNNER_FILE:  runner-rootless.json    # defaults to /data/runner.json
-      RUNNER_NAME:  forgejo-runner-rootless # defaults to forgejo-runner, used for registration
-      RUNNER_TOKEN: "${RUNNER_TOKEN}"
+      DEBUG: "true" # defaults to false, set to true to enable debug logging
+      SKIP_WAIT: "false" # defaults to false, set to true to skip the 10 second wait to allow for forgejo and docker-in-docker to start