preen Docker share guides for 0.4

docker/compose/zrok-public-share/docker-compose.yml

@@ -41,11 +41,6 @@ services:
     environment:
       HOME: /mnt
       PFXLOG_NO_JSON: "true"
-    volumes:
-      - zrok_env:/mnt/.zrok
-    environment:
-      HOME: /mnt
-      PFXLOG_NO_JSON: "true"
 
   # demo servers you can share with zrok
   zrok-test:

docs/guides/docker-share/docker_private_share_guide.md

@@ -32,6 +32,13 @@ First, let's create the private share.
     ZROK_ENABLE_TOKEN="8UL9-48rN0ua"
     ```
 
+1. If you are self-hosting zrok then it's important to set your API endpoint URL too. If you're using the hosted zrok service then you can skip this step.
+
+    ```bash
+    # file name ".env"
+    ZROK_API_ENDPOINT="https://zrok.example.com"
+    ```
+
 1. Run your Compose project to start sharing the built-in demo web server:
 
     ```bash

docs/guides/docker-share/docker_public_share_guide.md

@@ -27,6 +27,13 @@ To follow this guide you will need [Docker](https://docs.docker.com/get-docker/)
     ZROK_ENABLE_TOKEN="8UL9-48rN0ua"
     ```
 
+1. If you are self-hosting zrok then it's important to set your API endpoint URL too. If you're using the hosted zrok service then you can skip this step.
+
+    ```bash
+    # file name ".env"
+    ZROK_API_ENDPOINT="https://zrok.example.com"
+    ```
+
 1. Run your Compose project to start sharing the built-in demo web server:
 
     ```bash