Add Hakyll site generator and assets

Add site executable and Haskell modules (site.hs, ChaoDoc.hs,
SideNoteHTML.hs, Pangu.hs) to handle Pandoc/Hakyll compilation,
theorem/sidenote processing and CJK spacing. Add CSS, font files,
favicon, templates, Makefile, and a CSL bibliographic style. Update
.gitignore to ignore build artifacts.

makefile

@@ -0,0 +1,25 @@
+
+COMMANDS := build watch rebuild clean
+.PHONY: $(COMMANDS), publish
+
+# Set the default goal, so running 'make' without arguments will run 'make build'.
+.DEFAULT_GOAL := build
+
+# --- 
+$(COMMANDS): site
+	@echo "Running command: ./site $@"
+	-@./site $@
+
+
+# --- Rules ---
+# using relative symlinks should be fine since everything only works at ./
+
+
+site: src/site.hs src/ChaoDoc.hs
+	cabal build
+	ln -sf "$(shell cabal list-bin exe:site)" site
+
+# move from katex to mathjax
+# katex_cli:
+# 	cd katex_rust_fork && cargo build --release
+# 	ln -sf ./katex_rust_fork/target/release/katex_cli katex_cli