docs(README): update migration guide issue link (#493)

Author: sgoudham

README.md

@@ -128,7 +128,7 @@ set -gF window-status-current-format "#[bg=#{@ctp_mauve},fg=#{@ctp_crust}] ##I #
 ### Upgrading from v0.3
 
 Breaking changes have been introduced since 0.3, to understand how to migrate
-your configuration, see pinned issue [#291](https://github.com/catppuccin/tmux/issues/291).
+your configuration, see pinned issue [#487](https://github.com/catppuccin/tmux/issues/487).
 
 ## Recommended Default Configuration