Extend docs (#126)

* Add common errors and requirements to README

* Update issue template

Author: DeerMaximum

.github/ISSUE_TEMPLATE/issue.md

@@ -25,7 +25,16 @@ A clear and concise description of what the bug is.
 
 ## Debug log
 
-<!-- To enable debug logs check this https://www.home-assistant.io/components/logger/ -->
+<!-- To enable debug logs please add the code snipped below to your Home Assistant configuration.
+
+```yaml
+logger:
+  default: info
+  logs:
+    custom_components.ta_cmi: debug
+    ta_cmi: debug
+```
+-->
 
 ```text
 

.gitignore

@@ -4,3 +4,4 @@ venv
 .venv
 .coverage
 .idea
+dummy_server.py

README.md

@@ -24,6 +24,10 @@ Currently supported devices:
 > The loading time of the integration is extended by one minute per configured node on the C.M.I. to avoid triggering the rate limit.
 > The same applies to the setup process
 
+## Requirements
+
+* Credentials for an expert user on the C.M.I.
+
 {% if not installed %}
 ## Installation
 
@@ -69,6 +73,13 @@ In this step, individual channels can be customized, including the following pro
 To customize a channel, select the device,
 on which the channel is located, enter the channel number and finally select the channel type.
 
+## Common errors
+
+### "Unknown error occurred" on setup after ~60s
+
+This error occurs if the setup is done on a Home Assistant instance that is accessed through a reverse proxy or the Home Assistant Cloud. 
+In this case please connect **directly** to your instance and set up the integration.
+
 ## Supported data types
 
 | Device type | Inputs | Outputs | DL-inputs | System-values: General | System-values: Date | System-values: Time | System-values: Sun | System-values: Electrical power | Analog network inputs | Digital network inputs | M-Bus | Modbus | KNX | Analog logging | Digital logging |