Fix dockerfile. Again.

Docker builds were broken because the nim image does not add the Nimble
bin directory to PATH. This fix solves it by copying the nasher binary
to /usr/local/bin. As a side-effect, this fixes #42, allowing you to
pass your user/group to the docker command and own the files docker
generates.

dockerfile

@@ -1,16 +1,17 @@
-ARG nasher_version=0.13.0
-ARG nim_version=1.4.0
 # nwnsc compiler
 FROM nwneetools/nwnsc:latest as nwnsc
 # nim image
-FROM nimlang/nim:${nim_version}-alpine
+FROM nimlang/nim:alpine as nasher
 COPY --from=nwnsc usr/local/bin/nwnsc usr/local/bin/nwnsc
 COPY --from=nwnsc /nwn /nwn
-RUN nimble install nasher@#${nasher_version} -y \
-    && nasher config --nssFlags:"-n /nwn/data -o" \
+RUN apk add --no-cache bash
+ARG NASHER_VERSION="0.13.0"
+ENV PATH="/root/.nimble/bin:$PATH"
+RUN nimble install nasher@#${NASHER_VERSION} -y
+RUN nasher config --nssFlags:"-n /nwn/data -o" \
     && nasher config --installDir:"/nasher/install" \
     && nasher config --userName:"nasher"
 WORKDIR /nasher
-RUN bash -c 'mkdir -pv /nasher/install/{modules,erf,hak,tlk}'
+RUN bash -c "mkdir -pv /nasher/install/{erf,hak,modules,tlk}"
 ENTRYPOINT [ "nasher" ]
-CMD [ "list --quiet" ]
+CMD [ "--help" ]