readme: explain the Windows comment

Co-authored-by: Daniel Silverstone <dsilvers@digital-scurf.org>

Author: tshepang

README.md

@@ -72,7 +72,8 @@ available at this time are `minimal`, `default`, and `complete`:
 
 * The **minimal** profile includes as few components as possible to get a
 working compiler (`rustc`, `rust-std`, and `cargo`). It's recommended to use
-this component on Windows systems if you don't use local documentation, and in
+this component on Windows systems if you don't use local documentation (the large
+number of files can cause issues with some Antivirus systems), and in
 CI.
 * The **default** profile includes all the components previously installed by
 default (`rustc`, `rust-std`, `cargo`, and `rust-docs`) plus `rustfmt` and