ignore directory .zig-cache

The pre-release version of zig 0.13.0 was using 'zig-cache', but the
release version uses '.zig-cache'.

src/main.zig

@@ -244,7 +244,7 @@ fn configLocation(allocator: Allocator) ![]const u8 {
 }
 
 /// Reads the config file into a list of OtpAuthUrl.
-/// The caller is responsible to free the memory.
+/// The caller should use an arena allocator and free the memory eventually.
 fn read_config(allocator: Allocator, config_location: []const u8) !ArrayList(OtpAuthUrl) {
     const file = try std.fs.cwd().openFile(config_location, .{});
     defer file.close();
@@ -256,7 +256,6 @@ fn read_config(allocator: Allocator, config_location: []const u8) !ArrayList(Otp
 
     var line_no: usize = 1;
     while (try in_stream.readUntilDelimiterOrEofAlloc(allocator, '\n', 1024 * 1024)) |line| {
-        //defer allocator.free(line);
         if (line.len > 0 and std.mem.trim(u8, line, " \r").len > 0) {
             const authenticatorResult = parseOtpAuthUrl(allocator, line);
             if (authenticatorResult) |authenticator| {
@@ -264,7 +263,7 @@ fn read_config(allocator: Allocator, config_location: []const u8) !ArrayList(Otp
             } else |err| {
                 switch (err) {
                     error.InvalidOtpAuthUrl => {
-                        try std.io.getStdErr().writer().print("invalid otpauth url in line {d}\n", .{line_no});
+                        try std.io.getStdErr().writer().print("invalid otpauth url in line {d} in {s}\n", .{ line_no, config_location });
                     },
                     else => {
                         return err;