chore: minor updates to readme

Author: mefellows

README.md

@@ -85,7 +85,7 @@ pactflow-ai generate \
   --language typescript \
   --code ./src/product.js \
   --code ./src/api.js \
-  --template ./src/pact.test.template \
+  --template ./src/pact.test.template
 ```
 
 **With additional instructions (inline)**

src/test.instructions.txt

@@ -5,4 +5,5 @@
 * Use a 3 level hierarchy for tests
   1. Level 1 should be the API under test as a `describe` block e.g. "Product API"
   2. Level 2 should be the endpoint as a `describe` block e.g. "GET /products/:id", "POST /products"
-  3. Level 3 should be the scenario as a `test` block e.g. "Given a valid user, returns a 200", "Given an invalid user, returns a 400"
+  3. Level 3 should be the scenario as a `test` block e.g. "Given a valid user, returns a 200", "Given an invalid user, returns a 400"
+* Write test cases for the positive (HTTP 200) scenario and negative scenarios, specifically the case of 400, 401 and 404