fix(docs): use headings instead of bold for UIUX prompt steps

Satisfies markdownlint MD036 in UIUX_BRANDING_HANDOFF.md.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ulises-jeremias

docs/UIUX_BRANDING_HANDOFF.md

@@ -82,7 +82,7 @@ Flags:
 
 Interactive mode uses `questionary` with consistent markers: `qmark="?"`, `pointer=">"`.
 
-**1. Template selection (autocomplete)**
+#### 1. Template selection (autocomplete)
 
 When no `--template` is provided and interactive mode is on:
 
@@ -92,15 +92,15 @@ When no `--template` is provided and interactive mode is on:
 - Each choice shows a category badge, template name, slug, optional labels, and description
 - Final choice: `Use my own template URL` -> `questionary.text` for a custom URL
 
-**2. Extension selection (checkbox, two-step)**
+#### 2. Extension selection (checkbox, two-step)
 
 When no `--addons` are provided and interactive mode is on:
 
 - Step A: `Which kinds of extensions do you need?` -- category-level checkbox
 - Step B: per selected category, `{CategoryName} extensions` -- item-level checkbox
 - Choices are filtered by template type compatibility
 
-**3. Custom options (text / confirm)**
+#### 3. Custom options (text / confirm)
 
 From `cpa.config.json` or catalog `customOptions`: