Replace standalone workspace script with equivalent Makefile target

Makefile

@@ -35,6 +35,7 @@ REQUIREMENTS_TEMP := $(CURDIR)/temp-requirements.txt
 PIP_OUTDATED_TEMP := temp-pip-outdated.txt
 
 SHARED_JS_DIR := $(CURDIR)/apps/shared/static/js
+TMUX_SESSION_NAME := medley
 
 # Debugging tool to print the value of a variable.
 #
@@ -309,3 +310,18 @@ master-to-production: dummy
 	git merge master
 	git push
 	git checkout master
+
+workspace:
+# 0: Editor
+	tmux new-session -d -s "$(TMUX_SESSION_NAME)" bash
+	tmux send-keys -t "$(TMUX_SESSION_NAME)" "$(EDITOR) ." C-m
+
+# 1: Shell
+	tmux new-window -a -t "$(TMUX_SESSION_NAME)" bash
+	tmux send-keys -t "$(TMUX_SESSION_NAME)" "source venv/bin/activate" C-m
+
+# 2: Dev server
+	tmux new-window -a -t "$(TMUX_SESSION_NAME)" -n "devserver" "source venv/bin/activate; make serve"
+
+	tmux select-window -t "$(TMUX_SESSION_NAME)":0
+	tmux attach-session -t "$(TMUX_SESSION_NAME)"