toc: fix Nextclade URLs

Fixing Nextclade URLs to match the docs restructuring done for V3.

nextstrain/nextclade@2148fc2
nextstrain/nextclade@89e3ee7

src/index.rst

@@ -57,7 +57,7 @@ team and other Nextstrain users provide assistance.  For private inquiries,
     Exploring SARS-CoV-2 evolution <https://docs.nextstrain.org/projects/ncov/page/index.html>
     tutorials/creating-a-bacterial-pathogen-workflow
     tutorials/narratives-how-to-write
-    Analyzing genomes with Nextclade <https://docs.nextstrain.org/projects/nextclade/page/user/nextclade-web.html>
+    Analyzing genomes with Nextclade <https://docs.nextstrain.org/projects/nextclade/page/user/nextclade-web/index.html>
 
 .. toctree::
     :maxdepth: 1
@@ -81,7 +81,7 @@ team and other Nextstrain users provide assistance.  For private inquiries,
     Augur <https://docs.nextstrain.org/projects/augur/>
     Auspice <https://docs.nextstrain.org/projects/auspice/>
     Nextstrain CLI <https://docs.nextstrain.org/projects/cli/>
-    Nextclade CLI <https://docs.nextstrain.org/projects/nextclade/page/user/nextclade-cli.html>
+    Nextclade CLI <https://docs.nextstrain.org/projects/nextclade/page/user/nextclade-cli/index.html>
     Nextalign CLI <https://docs.nextstrain.org/projects/nextclade/page/user/nextalign-cli.html>
     nextstrain.org <https://docs.nextstrain.org/projects/nextstrain-dot-org/>