Remove tips & tricks from configuration documentation

Env substitution and includes are now deprecated and will be removed in a future version.

Signed-off-by: Steffen Vogel <steffen.vogel@opal-rt.com>

Author: steffen-vogel-opalrt

docs/node/config/index.md

@@ -77,83 +77,3 @@ paths = (
 	}
 )
 ```
-
-## Tips & Tricks
-
-### Use environment variables in your configuration {#node-config-envvars}
-
-VILLASnode substitutes any environment variables in you JSON and libconfig configuration files.
-
-To replace environment variables you must use the following syntax within any string value of your config: `${MYENV_VAR}`.
-
-**Note:** Non-string values can currently not be substituted by environment variables!
-
-#### Example
-
-<!-- convert to JSON -->
-```
-nodes = {
-	file_node = {
-		uri = "${FILE_PATH}"
-	}
-}
-```
-
-### Include other files into your configuration  {#node-config-include}
-
-VILLASnode can include other files into you configuration.
-This allows you to better structure and reuse parts of your configuration (e.g. the node definitions).
-
-File inclusion is handled via a special key in JSON objects named `@include`.
-The value of this key must point to an existing file on your file system.
-
-**Note:** libconfig supports inclusion of other files [out of the box via @include directives](http://hyperrealm.github.io/libconfig/libconfig_manual.html#Include-Directives). So this tip is mostly useful for JSON configuration files.
-
-#### Example
-
-```json title="params.json"
-{
-  "gain": 1.45,
-  "t_dt": 50e-6
-}
-```
-
-```json title="nodes.json"
-{
-  "test_node": {
-    "type": "file",
-    "in": {
-      "signals": {
-        "count": 12,
-        "type": "float"
-      }
-    }
-  },
-  "signal_node": {
-    "signal": "random",
-    "in": {
-      "hooks": [
-        {
-          "type": "lua",
-          "script": "myscript.lua",
-          "@include": "params.json"
-        }
-      ]
-    }
-  }
-}
-```
-
-```json title="experiment1.json"
-{
-  "nodes":{
-    "@include": "nodes.json"
-  },
-  "paths": [
-    {
-      "in": "signal_node",
-      "out": "test_node"
-	}
-  ]
-}
-```