added arm image

improved description (closes #1)

README.md

@@ -1,2 +1,95 @@
-# connectivity-check
-A self-hosted captive portal connectivity check
+# [connectivity-check](https://git.sp-codes.de/samuel-p/connectivity-check)
+
+[![Build Status](https://ci.sp-codes.de/api/badges/samuel-p/connectivity-check/status.svg)](https://ci.sp-codes.de/samuel-p/connectivity-check) [![License](https://img.shields.io/badge/license-MIT-orange)](#license) [![Docker Pulls](https://img.shields.io/docker/pulls/samuelph/connectivity-check)](https://hub.docker.com/r/samuelph/connectivity-check)
+
+A self-hosted captive portal connectivity check.
+
+## Usage
+
+Just run the following command:
+
+```bash
+docker run -d -p 80:80 -p 443:443 samuelph/connectivity-check
+```
+
+Or with docker-compose:
+
+```yaml
+version: '3.4'
+
+services:
+  connectivitycheck:
+    image: samuelph/connectivity-check
+    restart: always
+    ports:
+      - 80:80
+      - 443:443
+```
+
+## Run on a simple web space
+
+Instead of running the docker image you also can just use the following `.htaccess` file on your web server:
+
+```
+RewriteEngine On
+
+Header always set "X-NetworkManager-Status" "online"
+
+RewriteCond "%{REQUEST_FILENAME}" "(generate)?_?204"
+RewriteRule "(generate)?_?204" / [R=204,L]
+
+RewriteCond %{HTTPS} off
+RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
+```
+
+## Setup your devices
+
+### Android
+
+To change the Captive Portal Check in Android, you need a terminal app or a connection via ADB to a computer.
+
+To use `http` you can run the following commands with the respective method:
+
+```
+# settings put global captive_portal_use_https 0
+# settings put global captive_portal_http_url "http://connectivitycheck.sp-codes.de/generate204"
+```
+
+To use `https` you can use the following two commands:
+
+```
+# settings put global captive_portal_use_https 1
+# settings put global captive_portal_https_url "https://connectivitycheck.sp-codes.de/generate204"
+```
+
+Maybe you have to reboot your phone after updating the settings.
+
+If you are using AFWall+ you need to give access to _[1000] Android-System_ and in some cases _[10040] CaptivePortalLogin_ to make it work.
+
+For more information see [here](https://android.stackexchange.com/a/186995/288049).
+
+### Ubuntu
+
+In Ubuntu, the file `/etc/NetworkManager/NetworkManager.conf` must be changed. Add or change the following lines:
+
+```
+[connectivity]
+uri=https://connectivitycheck.sp-codes.de/generate204
+```
+
+Restart the network-manager:
+
+```
+sudo service network-manager restart
+```
+
+For more information see [here](https://askubuntu.com/q/1167177/920103).
+
+## Firefox
+
+Type [about:config](about:config) in the Firefox address bar and search for `captivedetect.canonicalURL` and `network.connectivity-service`. Set the URL values to `https://connectivitycheck.sp-codes.de/generate204`, the domain values to `connectivitycheck.sp-codes.de`. That's it.
+
+
+## License
+
+connectivity-check is Free Software: It is licensed under MIT (See [LICENSE](LICENSE) for more information).