chore: add bash-completion to devcontainer

This will add bash completion to the container so that tab completion
works for git commands in the terminal etc.

Signed-off-by: Andreas Kurz <[email protected]>

.devcontainer/Dockerfile

@@ -10,6 +10,7 @@ RUN add-apt-repository ppa:tiac-systems/doxygen
 RUN apt-get -y update && \
 	apt-get -y upgrade && \
 	apt-get install --no-install-recommends -y \
+	bash-completion \
 	doxygen \
 	graphviz \
 	mscgen \