Update devcontainer

Author: eel76-hmi

.devcontainer/Dockerfile

@@ -1,10 +1,10 @@
-FROM ubuntu:latest
+ARG VARIANT=ubuntu-20.04
+FROM mcr.microsoft.com/vscode/devcontainers/cpp:0-${VARIANT}
 
 RUN apt-get update && apt-get install -y \
-    build-essential \
-    cmake \
-    git \
-    clang \
-    lldb \
-    gdb \
+    python python3.8-venv pip pipx \
     && rm -rf /var/lib/apt/lists/*
+
+RUN pip install clang-format pre-commit
+
+RUN pre-commit install