Fixes #749 & #750 - ES: fix certificate import command; remove network config from instructions

Author: ralf401

install/elasticsearch/connect-configure-elasticsearch.rst

@@ -58,7 +58,7 @@ Add certificate to Zammad (Elasticsearch 8 and newer)
 
       .. code-block:: console
 
-         $ sudo cat /etc/elasticsearch/certs/http_ca.crt | zammad run rails r "SSLCertificate.create!(certificate: STDIN.read)"
+         $ sudo cat /etc/elasticsearch/certs/http_ca.crt | zammad run rails r 'SSLCertificate.create!(certificate: STDIN.read)'
 
    Add it via **UI**:
       In case you already have a running and configured Zammad, you can add the

install/elasticsearch/install-elasticsearch-9.rst

@@ -74,7 +74,7 @@ Add the Repository
    .. tab:: CentOS/RHEL
 
       Create the file ``/etc/yum.repos.d/elasticsearch.repo`` and add:
-      
+
       .. code-block:: text
 
          [elasticsearch]
@@ -127,20 +127,20 @@ Install Elasticsearch
 Configuration
 -------------
 
-Open ``/etc/elasticsearch/elasticsearch.yml`` and adjust/uncomment the
-following values:
-
-.. code-block:: yaml
+Optionally, check and configure Elasticsearch's configuration file which you can
+find under ``/etc/elasticsearch/elasticsearch.yml``.
 
-   network.host: 0.0.0.0
-   transport.host: 0.0.0.0
-
-Optional to increase the maximum context size to index:
+We recommend to adjust the maximum context size which should get indexed
+by Elasticsearch. Adjust it to a reasonable size like in the example:
 
 .. code-block:: yaml
 
    http.max_content_length: 400mb
 
+Additional configuration is out of scope of this documentation. In case your
+scenario needs additional configuration, have a look at
+`Elastic's configuration reference <https://www.elastic.co/docs/reference/elasticsearch/configuration-reference>`_.
+
 Start and Enable Elasticsearch
 ------------------------------