doc(ai4dev/README): fix font & typo

doc/ai4dev/README.md

@@ -43,14 +43,14 @@ Follow the [vibe coding](#vibe-coding) steps except as described below:
 * In your first prompt, attach test-suite.F90 with the lines from
   `module procedure laplacian` to `end procedure laplacian` removed.  If the
   LLM rejects ".F90" file extensions, change the name to "test-suite.txt".
-  Appened following to the prompt: "Inserting a correct response to this
-  prompt into the subdmodule subdomain_s and then compiling and running the
+  Append following to the prompt: "Inserting a correct response to this
+  prompt into the subdmodule `subdomain_s` and then compiling and running the
   attached program must generate output indicating that all tests pass."
 * In subsequent iterations, if replacing the laplacian procedure with the
   LLM's most recent response leads to compile-time or runtime errors or if any
   tests fail, update the test-suite program, replacing laplacian with the most
   recent LLM response. Attach the updated program to each prompt.
-* In the second bullet of vibe coding step 6, replace the suggested text wit
+* In the second bullet of vibe coding step 6, replace the suggested text with
   "Please fix the above errors that were generated by compiling the attached
   program, which contains an incorrect laplacian procedure."  If the program
   compiled but runtime errors resulted, replace "compiling" with "running" in