Improve log level documentation

Now, the documentation clearly states the purpose of each log level.
Also, the documentation for set_log_level is corrected:  libnitrokey
always prints to stderr.

1 files changed, 0 insertions, 1 deletions

diff --git a/TODO.md b/TODO.md
index b06de85..8538715 100644
--- a/TODO.md
+++ b/TODO.md
@@ -36,7 +36,6 @@
   - `NK_list_devices_by_cpuID`
   - `NK_connect_with_ID`
 - Fix timing issues with the `totp` and `totp_pin` test cases.
-- Improve log level documentation.
 - Clear passwords from memory.
 - Find a nicer syntax for the `write_config` test.
 - Fix segmentation faults when freeing string literals with old Nitrokey