add: dev workflow shenanigans

some shit

README.md

@@ -75,6 +75,26 @@ keep the minimum, and fail the moment fastwc loses a single case. GNU
 `wc` is used as an oracle the same way you'd use a broken clock:
 occasionally it's right, and it's the only one around.
 
+## Development
+
+The editor setup is one command:
+
+```sh
+make compile-commands   # compile_commands.json for clangd
+```
+
+clangd reads `.clangd`, `.clang-tidy`, and `.clang-format` — the style
+guide, enforced by robots. We use `bear` when it's installed; the
+fallback hand-rolls the single entry from the Makefile, because one
+source file doesn't need a database.
+
+- `make format` — make the code confess to the style guide
+- `make format-check` — verify without touching
+- `make lint` — clang-tidy, static analysis included
+
+`.editorconfig` and `.gitattributes` keep every editor honest. Your
+editor has opinions. So do we. Ours are in the repo.
+
 ## License
 
 MIT. Do whatever you want. We're not GNU, we won't sue you — we'll just