chore: add project documentation framework

.project-docs/10-decisions/adr-template.md

@@ -0,0 +1,33 @@
+# ADR-{number}: {decision title}
+
+## Status
+
+Proposed
+
+## Date
+
+{YYYY-MM-DD}
+
+## Context
+
+{context that made the decision necessary}
+
+## Decision
+
+{decision made}
+
+## Rationale
+
+{why this option was chosen}
+
+## Consequences
+
+- {positive or negative consequence}
+
+## Supersedes
+
+- {older ADR or decision, if any}
+
+## Related
+
+- {related doc or source file}