[brand] SearXNG - docs rename links and fix documentation

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

docs/utils/filtron.sh.rst

@@ -7,7 +7,7 @@
 
 .. sidebar:: further reading
 
-   - :ref:`searx filtron`
+   - :ref:`searxng filtron`
    - :ref:`architecture`
    - :ref:`installation` (:ref:`nginx <installation nginx>` & :ref:`apache
      <installation apache>`)

docs/utils/morty.sh.rst

@@ -14,7 +14,7 @@
    - :ref:`architecture`
    - :ref:`installation` (:ref:`nginx <installation nginx>` & :ref:`apache
      <installation apache>`)
-   - :ref:`searx morty`
+   - :ref:`searxng morty`
 
 To simplify installation and maintenance of a morty_ instance you can use the
 script :origin:`utils/morty.sh`.  In most cases you will install morty_ simply by
@@ -37,7 +37,7 @@ into this user account:
 
 .. hint::
 
-   To add morty to your SearXNG instance read chapter :ref:`searx morty`.
+   To add morty to your SearXNG instance read chapter :ref:`searxng morty`.
 
 Create user
 ===========

docs/utils/searx.sh.rst

@@ -24,7 +24,7 @@ In most cases you will install SearXNG simply by running the command:
 
    sudo -H ./utils/searx.sh install all
 
-The script adds a ``${SERVICE_USER}`` (default:``searx``) and installs searx
+The script adds a ``${SERVICE_USER}`` (default:``searx``) and installs SearXNG
 into this user account.  The installation is described in chapter
 :ref:`installation basic`.