Rename Pi-hole Core -> The pihole command, move it to main and add redirect.

Remove images that are not referenced anywhere else

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

docs/main/pihole-command.md

@@ -1,7 +1,3 @@
----
-title: The pihole command - Pi-hole documentation
----
-
 Pi-hole makes use of many commands, and here we will break down those required to administer the program via the command-line Interface.
 
 | Index | Invocation |

mkdocs.yml

@@ -120,8 +120,7 @@ nav:
     - 'Post-Install': main/post-install.md
     - 'Updating': main/update.md
     - 'Uninstalling': main/uninstall.md
-  - 'Pi-hole Core':
-    - 'The &nbsp<samp>pihole</samp>&nbsp command': core/pihole-command.md
+  - 'The &nbsp<samp>pihole</samp>&nbsp Command': main/pihole-command.md
   - 'Databases':
     - 'Overview': database/index.md
     - 'Query database': database/ftl.md
@@ -267,3 +266,4 @@ plugins:
         'ftldns/regex/overview.md': regex/overview.md
         'ftldns/regex/tutorial.md': regex/tutorial.md
         'database/gravity/example.md': group_management/example.md
+        'core/pihole-command.md': main/pihole-command.md