feat: refactor yasnippet

Put snippets in standard path

snippets/c-mode/fori

@@ -0,0 +1,8 @@
+# -*- mode: snippet -*-
+# name: for with loop variable
+# key: fori
+# --
+
+for (${1:size_t i = 0}; ${2:i < N}; ${3:++i}) {
+    $0
+}