docs: Use American spelling (#96)

Author: validcube

README.md

@@ -109,9 +109,9 @@ You can find the contribution guidelines [here](CONTRIBUTING.md).
 To build ReVanced Library,
 you can follow the [ReVanced documentation](https://github.com/ReVanced/revanced-documentation).
 
-## 📜 Licence
+## 📜 License
 
-ReVanced Library is licensed under the GPLv3 license. Please see the [licence file](LICENSE) for more information.
+ReVanced Library is licensed under the GPLv3 license. Please see the [license file](LICENSE) for more information.
 [tl;dr](https://www.tldrlegal.com/license/gnu-general-public-license-v3-gpl-3) you may copy, distribute and modify ReVanced Library as long as you track changes/dates in source files.
 Any modifications to ReVanced Library must also be made available under the GPL,
 along with build & install instructions.