chore: add copilot instructions

Author: aheckmann

.github/instructions/docs.instructions.md

@@ -0,0 +1,7 @@
+---
+applyTo: "docs/**/*.mdx, !docs/api/**/*.mdx"
+---
+
+Focus on documentation clarity and accuracy, ensuring that instructions are easy
+to follow and understand by a technical audience. Avoid suggesting changes that
+involve deleting existing content unless it is outdated or incorrect.