Update style-guide/template-style-guide.md

Update capitalization for Mailchimp

Co-authored-by: Daniel D. Beck <[email protected]>

style-guide/template-style-guide.md

@@ -77,7 +77,7 @@ For resources on making your writing more accessible, see:
 
 - [Writing accessible documentation - Google developer documentation style guide](https://developers.google.com/style/accessibility)
 - [Accessibility guidelines and requirements - Microsoft Manual of Style](https://docs.microsoft.com/en-us/style-guide/accessibility/accessibility-guidelines-requirements)
-- [Writing for Accessibility - MailChimp Content Style Guide](https://styleguide.mailchimp.com/writing-for-accessibility/)
+- [Writing for Accessibility - Mailchimp Content Style Guide](https://styleguide.mailchimp.com/writing-for-accessibility/)
 
 ## Inclusive and Bias-Free Writing