Simplify setting icon links in the navbar

What we're really doing is setting some default in the theme, and then
copying the template from pydata-sphinx-theme, but we can do the latter
using template inheritance.

Author: QuLogic

mpl_sphinx_theme/mpl_icon_links.html

@@ -1,52 +1,9 @@
-{%- block icon_links -%}
-{%- macro icon_link_nav_item(url, icon, name) -%}
-  {%- if url | length > 2 %}
-        <li class="nav-item">
-          <a class="nav-link" href="{{ url }}" rel="noopener" target="_blank" title="{{ _(name) }}">
-            <span><i class="{{ icon }}"></i></span>
-            <label class="sr-only">{{ _(name) }}</label>
-          </a>
-        </li>
-  {%- endif -%}
-{%- endmacro -%}
-{%- if theme_icon_links %}  
-      <ul id="navbar-icon-links" class="navbar-nav" aria-label="{{ _(theme_icon_links_label) }}">
-        {%- block icon_link_shortcuts -%}
-        {{ icon_link_nav_item(theme_github_url, "fab fa-github", "GitHub") -}}
-        {{ icon_link_nav_item(theme_gitlab_url, "fab fa-gitlab", "GitLab") -}}
-        {{ icon_link_nav_item(theme_bitbucket_url, "fab fa-bitbucket", "Bitbucket") -}}
-        {{ icon_link_nav_item(theme_twitter_url, "fab fa-twitter", "Twitter") -}}
-        {% endblock -%}
-        {%- for icon_link in theme_icon_links -%}
-        {{ icon_link_nav_item(icon_link["url"], icon_link["icon"], icon_link["name"]) -}}
-        {%- endfor %}
-      </ul>
-{%- else %}
-      <ul id="navbar-icon-links" class="navbar-nav" aria-label="{{ _(theme_icon_links_label) }}">
-        <li class="nav-item">
-          <a class="nav-link" href="https://gitter.im/matplotlib" rel="noopener" target="_blank" title="gitter">
-            <span><i class="fab fa-gitter"></i></span>
-            <label class="sr-only">Gitter</label>
-          </a>
-        </li>
-        <li class="nav-item">
-          <a class="nav-link" href="https://discourse.matplotlib.org" rel="noopener" target="_blank" title="discourse">
-            <span><i class="fab fa-discourse"></i></span>
-            <label class="sr-only">Discourse</label>
-          </a>
-        </li>
-        <li class="nav-item">
-          <a class="nav-link" href="https://github.com/matplotlib/matplotlib" rel="noopener" target="_blank" title="GitHub">
-            <span><i class="fab fa-github"></i></span>
-            <label class="sr-only">GitHub</label>
-          </a>
-        </li>
-        <li class="nav-item">
-          <a class="nav-link" href="https://twitter.com/matplotlib/" rel="noopener" target="_blank" title="twitter">
-            <span><i class="fab fa-twitter"></i></span>
-            <label class="sr-only">Twitter</label>
-          </a>
-        </li>
-      </ul>
-{%- endif %}  
-{%- endblock %}
+{%- if not theme_icon_links -%}
+  {%- set theme_icon_links = [
+    { "url": "https://gitter.im/matplotlib", "icon": "fab fa-gitter", "name": "Gitter" },
+    { "url": "https://discourse.matplotlib.org", "icon": "fab fa-discourse", "name": "Discourse" },
+    { "url": "https://github.com/matplotlib/matplotlib", "icon": "fab fa-github", "name": "GitHub" },
+    { "url": "https://twitter.com/matplotlib/", "icon": "fab fa-twitter", "name": "Twitter" },
+  ] -%}
+{%- endif -%}
+{% extends "navbar-icon-links.html" %}