docs(contributing): add CONTRIBUTING.md and link in README

Author: wick3dr0se

CONTRIBUTING.md

@@ -0,0 +1,72 @@
+### Project Scope & Philosophy
+
+Egor is a **graphics engine**, not a game engine
+
+Changes must:
+
+- Be broadly applicable to **apps, tools, and games**
+- Avoid assumptions about game-specific concepts (entities, scenes, physics, AI, etc.)
+- Keep APIs generic and composable
+
+If a change only makes sense for games, it likely does not belong in egor
+
+### Commit Messages
+
+Egor uses [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/). This helps `git-cliff` parse git history for generating clean release notes
+
+Format:
+type(scope): short description
+
+Examples:
+
+- fix(renderer): handle `begin_frame()` returning `None`
+- refactor(app): move window title into `AppConfig`
+- Avoid vague types/messages (e.g. `chore: stuff`, `fix: misc`)
+- docs(readme): clarify wasm setup
+
+Rules:
+
+- One logical change per commit
+- No unrelated commits in a single PR
+- Squash commits are preferred if history gets messy
+
+### Pull Requests
+
+Before opening a PR:
+
+- [ ] PR addresses **one** issue or feature
+- [ ] Commits are clean and logically separated
+- [ ] No unrelated refactors or formatting changes
+- [ ] Code builds on native **and** wasm (if applicable)
+- [ ] Public API changes are explained in the PR description
+
+Scope check:
+
+- Does this help **any 2D app**, or only a game?
+- Can this be implemented outside egor by the user?
+- Does this reduce flexibility or lock users into a pattern?
+- Would this make egor harder to use as a general-purpose graphics library?
+
+If unsure, open an issue or ask in [Discord](https://opensourceforce.net/discord) first
+
+Large or architectural changes should be discussed in an issue first
+
+PRs that mix unrelated changes may be closed or asked to split
+
+### Pre-PR Checklist
+
+Before submitting, make sure your changes pass these commands:
+
+```bash
+# Check formatting
+cargo fmt --all -- --check
+
+# Build and test native
+cargo test --all-targets --all-features --locked
+
+# Lint with Clippy
+cargo clippy --all-targets --all-features --locked -- -D warnings -A clippy::new-without-default
+
+# Verify documentation builds
+cargo doc --no-deps --document-private-items --locked
+```

README.md

@@ -99,8 +99,9 @@ dx serve --hot-patch
 
 ## Contributing
 
-**egor** is moving fast.. Got an idea, bugfix, or question?
-Check out some [issues](https://github.com/wick3dr0se/egor/issues), open a new one, drop a PR, or come hang in [Discord](https://opensourceforce.net/discord)
+**egor** is moving fast. Before opening a PR or submitting a change, please read [CONTRIBUTING.md](CONTRIBUTING.md)
+
+Check out some [issues](https://github.com/wick3dr0se/egor/issues), open a new one, drop a PR or come hang in [Discord](https://opensourceforce.net/discord)
 
 ---