Migrate Tray implementation to ksni crate (#152)

This change has several benefits, including:

- Removal of the separate tray application
- Removal of reliance on GTK3
- Everything being in one crate, in turn simplifying the codebase

Closes #84 and #128.

BUILDING.md

@@ -9,7 +9,7 @@ Celeste needs some packages installed in order to build:
 - [rustup](https://rustup.rs/)
 - [Go](https://go.dev/)
 - [just](https://github.com/casey/just)
-- Headers for GTK3, GTK4, Libadwaita, and Libappindicator (The best way I've found to find the needed packages is to try building as described below, and then looking at the output to see what the missing header files are. You can then install the needed packages via your package manager. This process is kind of tedious, but I don't know any other methods at the moment).
+- Headers for GTK4 and Libadwaita (The best way I've found to find the needed packages is to try building as described below, and then looking at the output to see what the missing header files are. You can then install the needed packages via your package manager. This process is kind of tedious, but I don't know any other methods at the moment).
 
 ## Building
 To build the project, run the following from the root of the repository:

CHANGELOG.md

@@ -6,6 +6,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.7.0] - 2023-10-07
+### Changed
+- Remove reliance on GTK3 and libappindicator.
+- Make tray functionality part of main application, instead of being a separate app.
+- Combine all application functionality into a singular crate.
+
+### Fixed
+- Fixed incorrect number of errors being reported in tray.
+- Fixed bug where tray icons would never change.
+
 ## [0.6.0] - 2023-10-05
 ### Added
 - Added Proton Drive support.