document min. rust version (closes #69)

Stephan Dilly · Stephan Dilly · commit 6d60f5b478ae · 2020-05-18T19:03:58.000+02:00
diff --git a/README.md b/README.md
@@ -58,6 +58,7 @@ brew install extrawurst/tap/gitui
 ### requirements
 
 install `rust`/`cargo`: https://www.rust-lang.org/tools/install
+min rust version: `1.42`
 
 ### cargo install
 
