(feat) Update dotfile scripts & tooling

- Update & split scripts
- Main package install script
- Fish / environment install script
- Dockerfile for testing locally

Dockerfile

@@ -0,0 +1,18 @@
+FROM ubuntu:mantic
+
+ARG USER=testuser
+
+RUN apt-get update && apt-get upgrade -y && \ 
+    apt-get install git fish build-essential jq vim curl sudo unzip fzf htop \
+    python3-dev python3-setuptools python3-pip python3-venv python3-smbus pipx liblzma-dev libffi-dev \
+    libssl-dev openssl zlib1g-dev libsqlite3-dev tk-dev libreadline-dev libbz2-dev locales -y \
+    && rm -rf /var/lib/apt/lists/* && localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
+
+ENV LANG en_US.utf8 
+
+RUN useradd -m -s /usr/bin/bash $USER
+RUN usermod -aG sudo $USER
+
+WORKDIR /app
+
+ENTRYPOINT [ "/bin/bash" ]