build core, basic and go variants and add template

core/Containerfile

@@ -0,0 +1,19 @@
+FROM alpine:latest
+
+# Install alpine packages
+RUN apk add --no-cache \
+  mandoc mandoc-doc less less-doc bash bash-doc bash-completion \
+  tmux tmux-doc neovim neovim-doc
+
+# Add shell configs
+COPY shell /etc
+
+# Add neovim config
+COPY nvim /etc/xdg/nvim
+ENV VIMINIT=":luafile /etc/xdg/nvim/init.lua"
+
+# Configure environment
+USER 1000:1000
+WORKDIR /work
+ENV HOME=/tmp TERM=xterm-256color LANG=en_US.UTF-8
+ENTRYPOINT ["/usr/bin/tmux", "new-session", "/usr/bin/nvim"]