build: use lefthook for pre-commit (#5248)

update docs
update nix-shell to auto install
rework custom pre-commit hooks to integrate better
add dockerfile for lefthook and integrate into drone
add some more hooks for formatting and linting some files

Co-authored-by: Darragh Elliott <me@delliott.net>
Reviewed-on: #5248
Co-authored-by: delliott <delliott@fsfe.org>
Co-committed-by: delliott <delliott@fsfe.org>

pre-commit.Dockerfile

@@ -0,0 +1,41 @@
+FROM debian:latest
+
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/
+
+# Install deps
+RUN apt-get update && apt-get install --yes --no-install-recommends \
+coreutils \
+curl \
+file \
+findutils \
+git \
+grep \
+libxml2 \
+libxml2-utils \
+libxslt1.1 \
+mediainfo \
+npm \
+perl-base \
+rsync \
+sed \
+shfmt
+
+# Install prettier
+RUN npm install -g prettier
+# Set uv project env, to persist stuff moving dirs 
+ENV UV_PROJECT_ENVIRONMENT=/root/.cache/uv/venv
+# Add vent to path
+ENV PATH="$UV_PROJECT_ENVIRONMENT/bin:$PATH"
+# Set the workdir
+WORKDIR /website-source
+
+# Copy the pyproject and build deps
+# Done in a seperate step for optimal docker caching
+COPY ./pyproject.toml .
+RUN uv sync --no-install-package fsfe_website_build --group dev
+# Copy everything else
+COPY . .
+
+ENTRYPOINT ["bash", "./pre-commit.entrypoint.sh"]
+
+