New docs

docs/reference-and-help/contributing-and-bug-reports.md

@@ -1,2 +1,34 @@
 # Contributing & Bug reports
 
+## Contribution workflow
+
+1. Fork `dexoron/dcr` (and `dexoron/dcr-site` if docs website changes are needed).
+2. Make focused changes.
+3. Run checks locally:
+
+```bash
+cargo fmt --all
+cargo clippy --all-targets --all-features -- -D warnings
+cargo check
+```
+
+4. Open a PR with short rationale and behavior impact.
+5. Update docs when CLI behavior changes.
+
+## Bug report checklist
+
+Include:
+
+1. DCR version (`dcr --version`).
+2. OS and compiler/toolchain version.
+3. Reproduction steps.
+4. Expected result.
+5. Actual result and full error output.
+6. Minimal reproducible project.
+
+## Where to report
+
+Use GitHub Issues in the relevant repository:
+
+- <https://github.com/dexoron/dcr>
+- <https://github.com/dexoron/dcr-site>