Add [package] rust-version field

Sh3Rm4n · Sh3Rm4n · commit d2d320ac3bed · 2021-10-26T22:19:55.000+02:00
diff --git a/Cargo.toml b/Cargo.toml
@@ -19,6 +19,7 @@ exclude = [
     ".markdownlint.yml"
 ]
 resolver = "2"
+rust-version = "1.52"
 
 [workspace]
 members = [
