fix anchor link in v2 post

Author: bradlc

src/pages/tailwindcss-v2/index.mdx

@@ -31,7 +31,7 @@ Tailwind CSS v2.0 is the first major update ever, including:
 
 - [**All-new color palette**](#all-new-color-palette), featuring 220 total colors and a new workflow for building your own color schemes
 - [**Dark mode support**](#dark-mode), making it easier than ever to dynamically change your design when dark mode is enabled
-- [**Extra wide 2XL breakpoint**](#extra-wide-2xl-breakpoint), for designing at 1536px and above
+- [**Extra wide 2XL breakpoint**](#extra-wide-2-xl-breakpoint), for designing at 1536px and above
 - [**New outline ring utilities**](#new-outline-ring-utilities), which are almost as good as if they would just make `outline-radius` a real thing
 - [**Utility-friendly form styles**](#utility-friendly-form-styles), a new form reset that makes it easy to customize form elements (even checkboxes) with just utility classes
 - [**Default line-heights per font-size**](#default-line-heights-per-font-size), because if we can't make using a 1.5 line-height with a 48px font illegal we should at least make it not the default