Update cursor-rules.mdc to fix unbalanced backticks

You had 2 opening backticks without closing the outer set.

For nested backticks, you use 4 on the outer set. 
See: https://python-markdown.github.io/extensions/fenced_code_blocks/

Not a biggie but just a little less thinking for Cursor to do if it's formatted correctly.

Author: joedevon

.cursor/rules/cursor-rules.mdc

@@ -37,7 +37,7 @@ How to add new cursor rules to the project
 
 5. Cursor rules have the following structure:
 
-```
+````
 ---
 description: Short description of the rule's purpose
 globs: optional/path/pattern/**/* 
@@ -62,4 +62,5 @@ function goodExample() {
 function badExample() {
   // Implementation not following guidelines
 }
-```
+```
+````