initial documentation attempt

+ add install and configuration documentations

README.md

@@ -1,4 +1,77 @@
 ## ejabberd-tools
+Repository containing various ejabberd tools.
+
+### tools
+#### metrics
+The metrics class is a tool  to gather and aggregate metrics data through the ejabberd rest/ xmlrpc interface.
+In addition to that  [Prometheus](https://prometheus.io/) and [InfluxDB](https://www.influxdata.com/) client
+utilizing the metrics class.
+
+### requirements
+The easiest way to setup a clean Python project environment is, to use a virtual environment inside the cloned
+repository directory. The following bash lines install the `python-virtualenv` module, create the virtual environment
+using Python3 and finally install all dependencies listed in the requirements file.
+
+```bash
+# Debian
+apt install python-virtualenv
+
+# Arch
+pacman -S python-virtualenv
+
+# mkdir venv
+virtualenv -p python3 venv/ -r requirements.txt
+```
+
+#### ejabberd
+It is required to have/ create a user account to operate the tools with. We strongly recommend to use a dedicated user
+to operate the api and to secure the account with a strong password.
+
+### configuration
+#### api permissions
+These configurations options first add the `mod_http_api` listener. Additionally the user `api_user@magicbroccoli.de` is
+added to the `acl` group, thus enabling him to access the `mod_http_api` configured in the `api_permissions` block.
+
+```yaml
+listen:
+  -
+    port: 5280
+    ip: "127.0.0.1"
+    tls: true # optional
+    module: ejabberd_http
+    request_handlers:
+      /api: mod_http_api
+
+acl:
+  api:
+    user: 
+      - "api_user@magicbroccoli.de"
+  loopback:
+    ip:
+      - 127.0.0.0/8
+      - ::1/128
+      - ::FFFF:127.0.0.1/128
+
+api_permissions:
+  "api access":
+    from:
+      - mod_http_api 
+    who:
+      access:
+        allow:
+          acl: api
+          acl: loopback # optional but recommended to restrict the api access to the local network
+    what:
+      - "*"
+      - "!stop"
+      - "!start"
+```
+
+#### ejabberd-metrics.yml
+The `ejabberd-metrics.yml` file is the central configuration file which is used by all current and future tools inside
+this repository.
+
+We provide a `ejabberd-metrics.yml.default` file which lists and explains which parameters should be set.
 
 ### error codes
 Lookup table for all custom error codes.