Install zip, upgrade pip

Dockerfile

@@ -1,9 +1,11 @@
 FROM python:3.12-slim
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    fontforge ttfautohint \
+    fontforge ttfautohint zip \
     && rm -rf /var/lib/apt/lists/*
 
+RUN pip install --upgrade pip
+
 RUN pip install --no-cache-dir fonttools
 
 WORKDIR /build

README.md

@@ -1,6 +1,6 @@
 # fntbld-oci
 
-A container image with font-building tools pre-installed:
+A Debian-based container image with font-building tools pre-installed:
 
 - **FontForge** — scriptable font editor
 - **ttfautohint** — auto-hinter for TrueType fonts