ignore/types: add file extensions for Crystal

It sounds like Projectfile is no longer being used,
but we should keep it around in case folks are
still using it. It's unlikely that its presence will
do much if any harm.

PR BurntSushi#1904

Author: kostya

crates/ignore/src/default_types.rs

@@ -40,7 +40,7 @@ pub const DEFAULT_TYPES: &[(&str, &[&str])] = &[
         "*.[ChH].in", "*.cc.in", "*.[ch]pp.in", "*.[ch]xx.in", "*.hh.in",
     ]),
     ("creole", &["*.creole"]),
-    ("crystal", &["Projectfile", "*.cr"]),
+    ("crystal", &["Projectfile", "*.cr", "*.ecr", "shard.yml"]),
     ("cs", &["*.cs"]),
     ("csharp", &["*.cs"]),
     ("cshtml", &["*.cshtml"]),