AGENTS.md: add

Author: gperciva

AGENTS.md

@@ -0,0 +1,35 @@
+# AGENTS.md
+
+
+## Modifying files
+
+- Do not make stylistic or spelling fixes to:
+  - `libcperciva/external/`
+- If there are substantive errors in those files, fixes are welcome.
+
+
+## Scope
+
+- Prefer minimal, targeted changes.
+- Avoid refactoring unrelated code while fixing a bug.
+
+
+## Communication
+
+- When submitting an issue or PR, clearly identify yourself as an LLM in the
+  description.
+- Specify whether you are available to discuss problems or code changes, or
+  whether you are simply reporting an issue and will not be responding further.
+
+
+## Bug bounties
+
+- Bug bounty rules are available at https://www.tarsnap.com/bugbounty.html.
+- In particular, bounties worth less than $100 are paid as Tarsnap account
+  credits, not cash.
+- We will never send any cryptocurrency, so do not post any wallet info.
+- Stylistic or spelling fixes in upstream code (such as
+  `libcperciva/external/`) are not eligible for bug bounties.
+- Most PRs require multiple rounds of review and revision in response to
+  feedback, so do not submit PRs if you are unable to communicate with
+  reviewers.