add devcontainer setup

docker/Dockerfile.core.dev

@@ -0,0 +1,19 @@
+FROM frigate:latest
+
+ARG USERNAME=vscode
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+# Create the user
+RUN groupadd --gid $USER_GID $USERNAME \
+    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME \
+    #
+    # [Optional] Add sudo support. Omit if you don't need to install software after connecting.
+    && apt-get update \
+    && apt-get install -y sudo \
+    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+RUN apt-get install -y git
+
+RUN pip3 install pylint black