[docs] switch sphinx theme from pallets to furo (#3408)

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

docs/conf.py

@@ -1,8 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
-import  sys, os
+import sys, os
 from pathlib import Path
-from pallets_sphinx_themes import ProjectLink
 
 from searx import get_setting
 from searx.version import VERSION_STRING, GIT_URL, GIT_BRANCH
@@ -98,7 +97,6 @@ extlinks['pull-searx'] = ('https://github.com/searx/searx/pull/%s', 'PR %s')
 extlinks['origin'] = (GIT_URL + '/blob/' + GIT_BRANCH + '/%s', 'git://%s')
 extlinks['patch'] = (GIT_URL + '/commit/%s', '#%s')
 extlinks['docs'] = (DOCS_URL + '/%s', 'docs: %s')
-extlinks['pypi'] = ('https://pypi.org/project/%s', 'PyPi: %s')
 extlinks['man'] = ('https://manpages.debian.org/jump?q=%s', '%s')
 #extlinks['role'] = (
 #    'https://www.sphinx-doc.org/en/master/usage/restructuredtext/roles.html#role-%s', '')
@@ -117,7 +115,6 @@ extensions = [
     'sphinx.ext.viewcode',
     "sphinx.ext.autodoc",
     "sphinx.ext.intersphinx",
-    "pallets_sphinx_themes",
     "sphinx_issues", # https://github.com/sloria/sphinx-issues/blob/master/README.rst
     "sphinx_jinja",  # https://github.com/tardyp/sphinx-jinja
     "sphinxcontrib.programoutput",  # https://github.com/NextThought/sphinxcontrib-programoutput
@@ -158,15 +155,29 @@ issues_github_path = "searxng/searxng"
 
 # HTML -----------------------------------------------------------------
 
+html_theme = "furo"
+
+html_sidebars = {
+    "**": [
+        "sidebar/scroll-start.html",
+        "sidebar/brand.html",
+        "sidebar/search.html",
+        "sidebar/navigation.html",
+        "sidebar/ethical-ads.html",
+        "sidebar/scroll-end.html",
+    ]
+}
+
+html_static_path = ['_static']
+
+html_css_files = [
+    'searxng.css',
+]
+
 # https://searxng.github.io/searxng --> '/searxng/'
 # https://docs.searxng.org --> '/'
 notfound_urls_prefix = '/'
 
-sys.path.append(os.path.abspath('_themes'))
-sys.path.insert(0, os.path.abspath("../"))
-html_theme_path = ['_themes']
-html_theme = "searxng"
-
 # sphinx.ext.imgmath setup
 html_math_renderer = 'imgmath'
 imgmath_image_format = 'svg'
@@ -174,31 +185,6 @@ imgmath_font_size = 14
 # sphinx.ext.imgmath setup END
 
 html_show_sphinx = False
-html_theme_options = {"index_sidebar_logo": True}
-html_context = {"project_links": [] }
-html_context["project_links"].append(ProjectLink("Source", GIT_URL + '/tree/' + GIT_BRANCH))
-
-if WIKI_URL:
-    html_context["project_links"].append(ProjectLink("Wiki", WIKI_URL))
-if PUBLIC_INSTANCES:
-    html_context["project_links"].append(ProjectLink("Public instances", PUBLIC_INSTANCES))
-if ISSUE_URL:
-    html_context["project_links"].append(ProjectLink("Issue Tracker", ISSUE_URL))
-if PRIVACYPOLICY_URL:
-    html_context["project_links"].append(ProjectLink("Privacy Policy", PRIVACYPOLICY_URL))
-if CONTACT_URL:
-    html_context["project_links"].append(ProjectLink("Contact", CONTACT_URL))
-
-html_sidebars = {
-    "**": [
-        "globaltoc.html",
-        "project.html",
-        "relations.html",
-        "searchbox.html",
-        "sourcelink.html"
-    ],
-}
-singlehtml_sidebars = {"index": ["project.html", "localtoc.html"]}
 html_logo = "../client/simple/src/brand/searxng-wordmark.svg"
 html_title = "SearXNG Documentation ({})".format(VERSION_STRING)
 html_show_sourcelink = True