update readme and docker file

Dockerfile

@@ -1,16 +1,18 @@
-FROM python:2.7
-LABEL org.opencontainers.image.authors="Eric Taieb Walch <teknologist@gmail.com>"
-
-RUN mkdir /app && \
-cd /app && \
-git clone https://github.com/rshipp/python-nut2.git && \
-cd python-nut2 && \
-python setup.py install && \
-cd .. && \
-git clone https://github.com/rshipp/webNUT.git && cd webNUT && \
-pip install -e .
-
+FROM python:3.11-alpine
 
+RUN apk update \
+&& apk upgrade --available \
+&& apk add git tzdata \
+&& mkdir /app \
+&& cd /app \
+&& git clone https://github.com/rshipp/python-nut2.git \
+&& cd python-nut2 \
+&& python setup.py install \
+&& cd .. \
+&& git clone https://github.com/rshipp/webNUT.git \
+&& cd webNUT \
+&& pip install -e . \
+&& rm -rf /var/cache/apk/*
 
 COPY /docker-entrypoint.sh /docker-entrypoint.sh
 RUN chmod +x /docker-entrypoint.sh