add(function): added function to quickly open a new rust codewars env

.config/fish/functions/codewars_rust.fish

@@ -0,0 +1,24 @@
+function codewars_rust
+
+    if count $argv >/dev/null
+        mkdir ~/repos/codewars/Rust/"$argv"
+        mkdir ~/repos/codewars/Rust/"$argv"/src
+        touch ~/repos/codewars/Rust/"$argv"/src/main.rs
+        echo >~/repos/codewars/Rust/"$argv"/Cargo.toml "\
+[package]
+name = \"$argv\"
+version = \"1.0.0\"
+authors = [ \"Léana 江 <leana.jiang@icloud.com>\" ]
+
+[dependencies]
+
+[[bin]]
+name = \"main\"\
+"
+        codium ~/repos/codewars/Rust/"$argv"
+    else
+        echo "You must provide a new project name"
+        return 1
+    end
+
+end