Update dependencies docs image and fix non-working badge

docs/Dockerfile

@@ -1,5 +1,5 @@
 # Convert .rst files to .html in temporary build container
-FROM python:3.8-alpine3.14 AS build
+FROM python:3.12.0-alpine3.18 AS build
 
 ARG version=master
 ENV VERSION=$version
@@ -16,7 +16,7 @@ RUN apk add --no-cache --virtual .build-deps \
 
 
 # Build nginx deployment image including generated html
-FROM nginx:1.21-alpine
+FROM nginx:1.25.3-alpine
 
 ARG version=master
 ARG pinned_version=master

docs/index.rst

@@ -8,8 +8,8 @@ Mailu
 .. image:: https://img.shields.io/github/stars/mailu/mailu.svg?label=github&logo=github&maxAge=2592000
    :target: https://github.com/mailu/mailu
 
-.. image:: https://img.shields.io/docker/pulls/mailu/admin.svg?label=docker&maxAge=2592000
-   :target: https://hub.docker.com/u/mailu/
+.. image:: https://img.shields.io/badge/Mailu-latest_release-blue
+   :target: https://github.com/Mailu/Mailu/releases
 
 .. image:: https://img.shields.io/badge/matrix-%23mailu%3Atedomum.net-7bc9a4.svg
    :target: https://matrix.to/#/#mailu:tedomum.net

docs/requirements.txt

@@ -1,5 +1,5 @@
 recommonmark==0.7.1
-Sphinx==5.2.0
+Sphinx==7.2.6
 sphinx-autobuild==2021.3.14
-sphinx-rtd-theme==1.0.0
-docutils==0.16
+sphinx-rtd-theme==1.3.0
+docutils==0.18.1