Adding the limit increase footnote to the 50k limit. (#19384)

Author: Oxyjun

src/content/docs/d1/platform/limits.mdx

@@ -10,7 +10,7 @@ import { Render } from "~/components";
 
 | Feature                                                                                                             | Limit                                             |
 | ------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- |
-| Databases                                                                                                           | 50,000 (Workers Paid) / 10 (Free)                 |
+| Databases                                                                                                           | 50,000 (Workers Paid)[^1] / 10 (Free)                 |
 | Maximum database size                                                                                               | 10 GB (Workers Paid) / 500 MB (Free)              |
 | Maximum storage per account                                                                                         | 250 GB (Workers Paid)[^1] / 5 GB (Free)           |
 | [Time Travel](/d1/reference/time-travel/) duration (point-in-time recovery)                                         | 30 days (Workers Paid) / 7 days (Free)            |