🌱 docs(footer): Add trademark disclaimer (#3132)

* docs(footer): Add trademark disclaimer

* Amend copyright on doc's footer

Co-authored-by: Rob Scott <rob.scott87@gmail.com>

* docs(copyright): Add trailing line

---------

Co-authored-by: Rob Scott <rob.scott87@gmail.com>

mkdocs.yml

@@ -3,6 +3,7 @@ repo_url: https://github.com/kubernetes-sigs/gateway-api
 repo_name: kubernetes-sigs/gateway-api
 site_dir: site
 docs_dir: site-src
+trademark: https://www.linuxfoundation.org/legal/trademark-usage
 extra_css:
   - stylesheets/extra.css
 extra_javascript:

site-src/overrides/partials/copyright.html

@@ -0,0 +1,40 @@
+<!--
+  Copyright (c) Kubernetes Authors and Martin Donath <martin.donath@squidfunk.com>
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to
+  deal in the Software without restriction, including without limitation the
+  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+  sell copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+  IN THE SOFTWARE.
+-->
+
+<!-- Copyright and theme information -->
+<div class="md-copyright">
+  {% if config.trademark %}
+  <p>
+    The Linux Foundation has registered trademarks and uses trademarks. For a list of trademarks of The Linux Foundation,
+    please see our <a href="{{ config.trademark }}">Trademark Usage page</a>.
+  </p>
+  {% endif %}
+  {% if not config.extra.generator == false %}
+    Made with
+    <a
+      href="https://squidfunk.github.io/mkdocs-material/"
+      target="_blank" rel="noopener"
+    >
+      Material for MkDocs
+    </a>
+  {% endif %}
+</div>