chore: add styleguide.md for use with gemini (#15611)

scotthart · web-flow · commit 0e5f99647871 · 2025-10-13T10:00:45.000-04:00
diff --git a/.gemini/styleguide.md b/.gemini/styleguide.md
@@ -0,0 +1,5 @@
+This repository mostly follows the Google C++ style guide found at
+https://google.github.io/styleguide/cppguide.html.
+
+Notably, this repository only allows language features and libraries found in
+C++14.
