fix dead docs link and add dark reader meta tag

Author: topi314

docs/api/rest.md

@@ -751,7 +751,7 @@ When `identifier` is used, Lavalink will try to resolve the identifier as a sing
 
 Response:
 
-[Player](#Player) object
+[Player](#player) object
 
 <details markdown="1">
 <summary>Example Payload</summary>

docs/overrides/main.html

@@ -1,3 +1,7 @@
+{%- block extrahead -%}
+    <meta name="darkreader" content="">
+{%- endblock -%}
+
 {% extends "base.html" %}
 
 {% block announce %}