Add warning for removal of dataframes cargo feature

Author: devyn

blog/2024-05-28-nushell_0_94_0.md

@@ -18,6 +18,10 @@ Nu 0.94.0 is available as [pre-built binaries](https://github.com/nushell/nushel
 
 As part of this release, we also publish a set of optional plugins you can install and use with Nu. To install, use `cargo install nu_plugin_<plugin name>`.
 
+::: warning
+The `dataframes` cargo feature [has been removed in this release](#removal-of-deprecated-features-toc), after being deprecated in 0.93.0. You may need to modify your build scripts if you have been building Nushell from source.
+:::
+
 # Table of content
 
 - [_Themes of this release / New features_](#themes-of-this-release-new-features-toc)