message: Added file extension to introduction
  Added file extension to introduction
diff: @@ -7,6 +7,7 @@ be provided to it, and it will do its best to describe it.
  ```rune
  {{#include ../../scripts/book/getting_started/dbg.rn}}
  ```
  +> **Note**: by convention Rune uses files ending in .rn.
  ```text
  $> cargo run --bin rune -- run scripts/book/getting_started/dbg.rn
  