Clarification regarding licenses

[daniel-evers]

The repository itself has only a MIT license file in its root directory. If you take a look at the source files, it appears to be a dual MIT/BSD license.

Regarding this, I have some questions for clarification.

• Is it possible to update the corresponding license file in the root directory to immediately recognize the dual license?
• Which BSD license is used exactly (1, 2, 3, 4, ...)?
• It is possible to use SPDX identifiers?
• Is it beneficial to create a pull request (I ask because this project doesn't seem to be maintained)?