Fix link to libcurl section of everything curl

Author: saimen

libcurl/_index.html

@@ -67,7 +67,7 @@
  Check out our <a href="using/">using libcurl</a> page for general hints and
  advice and manpages for <a href="c/allfuncs.html">every function</a> and
  option. Also, check out
- the <a href="https://everything.curl.dev/libcurl.html">libcurl section of
+ the <a href="https://everything.curl.dev/libcurl/index.html">libcurl section of
  everything curl</a>.
 
 <p>