Improve docker builds and documentation

* Refactor Dockerfile to build from source instead of pypi
* Include an additional dockerfile for building from pypi
* Update readme documentation for docker to specify image sources and docker-specific run instructions

Dockerfile

@@ -1,19 +1,34 @@
 FROM python:3-alpine
 
+# Based on the work of Jonathan Boeckel <jonathanboeckel1996@gmail.com>
+# https://gitlab.com/Joniator/docker-maloja
+# https://github.com/Joniator
+
 WORKDIR /usr/src/app
 
+# Copy project into dir
+COPY . .
+
 RUN apk add --no-cache --virtual .build-deps \
     gcc \
     libxml2-dev \
     libxslt-dev \
-    py3-pip \
     libc-dev \
-    linux-headers \
-    && \
+    # install pip3
+    py3-pip \
+    linux-headers && \
     pip3 install psutil && \
-    pip3 install --upgrade --no-cache-dir malojaserver && \
+    # use pip to install maloja project requirements
+    pip3 install --no-cache-dir -r requirements.txt && \
+    # use pip to install maloja as local project
+    pip3 install /usr/src/app && \
     apk del .build-deps
 
-EXPOSE 42010
+RUN apk add --no-cache tzdata
 
-ENTRYPOINT maloja run
+# expected behavior for a default setup is for maloja to "just work"
+ENV MALOJA_SKIP_SETUP=yes
+
+EXPOSE 42010
+# use exec form for better signal handling https://docs.docker.com/engine/reference/builder/#entrypoint
+ENTRYPOINT ["maloja", "run"]