First, upload your macro to the "Macro Library" section/category.
See How to post/upload your script/macro.
Then just edit the OP of the Best Macro List , and add your Macros to the appropriate section, following the style that is used.
Then it is usually good idea to select/quote the Macros you have added, and enter a new post so that everyone is notified. Just editing the OP does NOT generate notifications.
When I get the notification, I will double-check your updates for you this time.
To edit a "wiki" post, just click on the "wiki edit icon" in the top right of the post.
Macros are sorted first by Category, then alphabetically by Macro name.