Add piping, Add type builtin, Add command -v builtin

src/builtin/cmds/cd.zig

@@ -2,7 +2,7 @@ const std = @import("std");
 
 const types = @import("../types.zig");
 
-pub fn execute(ctx: types.BuiltinCommandContext) !void {
+pub fn execute(ctx: types.CommandContext) !void {
     const path = if (ctx.argv.len >= 2)
         ctx.argv[1]
     else