Add Makefile (#123)

.gitignore

@@ -127,3 +127,6 @@ dmypy.json
 
 # Pyre type checker
 .pyre/
+
+# Sphinx docs
+_build

Makefile

@@ -0,0 +1,93 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+PYTHON        = python3
+VENVDIR       = ./.venv
+SPHINXBUILD   = $(VENVDIR)/bin/sphinx-build
+SPHINXOPTS    = --fail-on-warning --keep-going
+BUILDDIR      = _build
+BUILDER       = html
+JOBS          = auto
+SPHINXLINT    = $(VENVDIR)/bin/sphinx-lint
+
+# Internal variables.
+ALLSPHINXOPTS   = --builder $(BUILDER) \
+                  --doctree-dir $(BUILDDIR)/doctrees \
+                  --jobs $(JOBS) \
+                  $(SPHINXOPTS) \
+                  docs $(BUILDDIR)/$(BUILDER)
+
+.PHONY: help
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  venv       to create a venv with necessary tools"
+	@echo "  html       to make standalone HTML files"
+	@echo "  htmlview   to open the index page built by the html target in your browser"
+	@echo "  htmllive   to rebuild and reload HTML files in your browser"
+	@echo "  clean      to remove the venv and build files"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  lint       to lint all the files"
+
+.PHONY: clean
+clean: clean-venv
+	-rm -rf $(BUILDDIR)/*
+
+.PHONY: clean-venv
+clean-venv:
+	rm -rf $(VENVDIR)
+
+.PHONY: venv
+venv:
+	@if [ -d $(VENVDIR) ] ; then \
+		echo "venv already exists."; \
+		echo "To recreate it, remove it first with \`make clean-venv'."; \
+	else \
+		$(MAKE) ensure-venv; \
+	fi
+
+.PHONY: ensure-venv
+ensure-venv:
+	@if [ ! -d $(VENVDIR) ] ; then \
+		echo "Creating venv in $(VENVDIR)"; \
+		if uv --version > /dev/null; then \
+			uv venv $(VENVDIR); \
+			VIRTUAL_ENV=$(VENVDIR) uv pip install -r requirements.txt; \
+		else \
+			$(PYTHON) -m venv $(VENVDIR); \
+			$(VENVDIR)/bin/python3 -m pip install --upgrade pip; \
+			$(VENVDIR)/bin/python3 -m pip install -r requirements.txt; \
+		fi; \
+		echo "The venv has been created in the $(VENVDIR) directory"; \
+	fi
+
+.PHONY: html
+html: ensure-venv
+	$(SPHINXBUILD) $(ALLSPHINXOPTS)
+
+.PHONY: linkcheck
+linkcheck: BUILDER = linkcheck
+linkcheck: html
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/$(BUILDER)/output.txt."
+
+.PHONY: htmlview
+htmlview: html
+	$(PYTHON) -c "import os, webbrowser; webbrowser.open('file://' + os.path.realpath('_build/html/index.html'))"
+
+.PHONY: htmllive
+htmllive: SPHINXBUILD = $(VENVDIR)/bin/sphinx-autobuild
+# Arbitrarily selected ephemeral port between 49152–65535
+# to avoid conflicts with other processes:
+htmllive: SPHINXOPTS = --re-ignore="/\.idea/|/venv/" --open-browser --delay 0 --port 55303
+htmllive: html
+
+.PHONY: lint
+lint: venv
+	if uv --version > /dev/null; then \
+		$(VENVDIR)/bin/python3 -m pre_commit --version > /dev/null || VIRTUAL_ENV=$(VENVDIR) uv pip install pre-commit; \
+	else \
+		$(VENVDIR)/bin/python3 -m pre_commit --version > /dev/null || $(VENVDIR)/bin/python3 -m pip install pre-commit; \
+	fi;
+	$(VENVDIR)/bin/python3 -m pre_commit run --all-files