chore: add MIT License (#13)

Add MIT License to ensure proper licensing and legal compliance. This
change addresses the licensing requirements for the project and provides
clear permissions to users.

The MIT License is a permissive open-source license widely used for
software projects. It allows users to freely use, modify, and distribute
the software, either in its original form or with modifications, while
providing a disclaimer of warranty. This license is known for its
simplicity and flexibility, making it a popular choice for many
open-source projects.

Signed-off-by: Lapotor <[email protected]>

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 RadioRoster
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.