refactor(web/tvl/template): Move footer into a separate target

This makes it possible for the footer to be reused in other places,
e.g. when templating blog posts (which do not go through
//web/tvl/template (yet)).

Change-Id: Ia8ab0e1c6db4f76b4de49239e11a4474038f60ae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3773
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

web/tvl/footer/default.nix

@@ -0,0 +1,21 @@
+# Footer fragment for TVL homepages, used by //web/tvl/template for
+# our static pages and also via //web/blog for blog posts.
+{ lib, ... }:
+
+args: ''
+  <p class="footer">
+    <a class="uncoloured-link" href="https://at.tvl.fyi/?q=%2F%2FREADME.md">code</a>
+    |
+    <a class="uncoloured-link" href="https://cl.tvl.fyi/">reviews</a>
+    |
+    <a class="uncoloured-link" href="https://tvl.fyi/builds">ci</a>
+    |
+    <a class="uncoloured-link" href="https://b.tvl.fyi/">bugs</a>
+    |
+    <a class="uncoloured-link" href="https://todo.tvl.fyi/">todos</a>
+    |
+    <a class="uncoloured-link" href="https://atward.tvl.fyi/">search</a>
+    '' + lib.optionalString (args ? extraFooter) args.extraFooter + ''
+  </p>
+  <p class="lod">ಠ_ಠ</p>
+''

web/tvl/template/default.nix

@@ -37,21 +37,7 @@ runCommandNoCC "index.html" {
   footerPart = ''
     <hr>
     <footer>
-      <p class="footer">
-        <a class="uncoloured-link" href="https://at.tvl.fyi/?q=%2F%2FREADME.md">code</a>
-        |
-        <a class="uncoloured-link" href="https://cl.tvl.fyi/">reviews</a>
-        |
-        <a class="uncoloured-link" href="https://tvl.fyi/builds">ci</a>
-        |
-        <a class="uncoloured-link" href="https://b.tvl.fyi/">bugs</a>
-        |
-        <a class="uncoloured-link" href="https://todo.tvl.fyi/">todos</a>
-        |
-        <a class="uncoloured-link" href="https://atward.tvl.fyi/">search</a>
-        '' + lib.optionalString (args ? extraFooter) extraFooter + ''
-      </p>
-      <p class="lod">ಠ_ಠ</p>
+      ${depot.web.tvl.footer args}
     </footer>
   </body>
   '';