chore: update documentation font size

[pikann]

Summary

• Increase the font size of document and folder names in the sidebar Documentation section from text-xs (12px) to text-sm (14px) for better readability
• Bump the inline rename input to match, so the text doesn't change size when switching into rename mode

Test plan

• Open a project and expand the Documentation section in the sidebar
• Confirm document and folder names render at the larger size
• Rename a document/folder and confirm the inline input matches the new size