chore: fix file type ext for arch doc

docs/architecture/005-new-162-fontsize-token.md

@@ -0,0 +1,15 @@
+# Introducing a 26px Font Size Token (162)
+
+## Background
+
+The current design system includes a sequence of font size tokens that range from 050 to 500, covering a variety of common font sizes. However, there is no token for a 26px font size, which falls between the existing 24px (likely token 150) and 28px (likely token 175).
+
+**To address this gap, we propose adding a new token:** 162, representing the 26px font size. While the naming of tokens generally follows a predictable sequence, we have previously included some exceptions where unique naming conventions better suited our design needs. The addition of token 162 aligns with this flexibility.
+
+### Rationale
+
+- **Visual consistency:** A 26px size provides a finer granularity of choice between 24px and 28px, allowing for more precise typography adjustments.
+
+- **Existing use cases:** The need for a 26px font size has emerged based on design reviews and accessibility considerations, particularly for headings and larger body text in certain layouts.
+
+- **Token flexibility:** The system already accommodates some non-sequential naming conventions. Introducing token 162 for 26px continues this flexible approach while maintaining overall consistency.