differentiate numerical imm and label imm,

implement assembler,
add binary file outputs to gitignore,
add development container for assembler

.devcontainer/Dockerfile

@@ -0,0 +1,6 @@
+FROM python:slim
+WORKDIR /
+RUN apt-get -y update; apt-get -y upgrade
+RUN apt-get -y install git binutils
+COPY requirements.txt .
+RUN pip install -r requirements.txt