Add logo for plugin (#73)

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Added
 
+- Plugin logo for easier recognition
+
 ### Changed
 
 - Update Grammar-Kit: 2021.1.2 -> 2022.3.2

NOTICE

@@ -0,0 +1,19 @@
+License Notice
+
+   NIX SNOWFLAKE
+
+   This project contains variants of the Nix Snowflake (the logo of NixOS).
+   The Nix Snowflake is designed by Tim Cuthbertson (@timbertson) and is
+   made available under a CC-BY license.
+
+   Origin:  https://github.com/NixOS/nixos-artwork/tree/master/logo
+   License: https://creativecommons.org/licenses/by/4.0/
+
+   The image files within this repository may have been modified to comply
+   with JetBrains' Guidelines. The modifications may include resizing the
+   image, refitting the image, and compressing the image by removing
+   invisible elements.
+
+   src/main/resources/META-INF/pluginIcon.svg
+   src/main/resources/META-INF/pluginIcon_dark.svg
+   src/main/resources/org/nixos/idea/icon/nixos-icon.png

README.md

@@ -66,6 +66,12 @@ running the `build` task in Gradle.
 You should then find the plugin at
 `build/distributions/NixIDEA-<version>.zip`.
 
+## Credits
+
+The *Nix Snowflake* (logo of NixOS) is designed by Tim Cuthbertson (@timbertson).
+It is made available under [CC-BY license](https://creativecommons.org/licenses/by/4.0/)
+at [NixOS/nixos-artwork](https://github.com/NixOS/nixos-artwork/tree/master/logo).
+The variants used by this plugin may have been modified to comply with JetBrains' Guidelines.
 
 [build-status]:
 <https://github.com/NixOS/nix-idea/actions/workflows/build.yml?query=branch%3Amaster>