chore: Add contributing guidelines

CONTRIBUTING.md

@@ -0,0 +1,15 @@
+# Contributing to FluffyChat
+Contributions are always welcome. Yet we might lack manpower to review all of them in time.
+
+To improve the process please make sure that you read the following guidelines carefully:
+
+## Contributing Guidelines
+
+1. Always create a Pull Request for any changes.
+2. Whenever possible please make sure that your Pull Request only contains **one** commit. Cases where multiple commits make sense are very rare.
+3. Every Pull Request should change only one thing. For bigger changes it is often better to split them up in multiple Pull Requests.
+4. [Sign your commits](https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits).
+5. Format the commit message as [Conventional Commits](https://www.conventionalcommits.org).
+6. Format (`flutter format lib`) and sort impots (`dart run import_sorter:main --no-comments`) in all code files.
+7. For bigger or complex changes (more than a couple of code lines) write an issue or refer to an existing issue and ask for approval from the maintainers (@krille-chan) **before** starting to implement it. This way you reduce the risk that your Pull Request get's declined.
+8. Prefer simple and easy to maintain solutions over complexity and fancy ones.

pubspec.lock

@@ -1123,7 +1123,7 @@ packages:
     description:
       path: "."
       ref: HEAD
-      resolved-ref: "99745b0e210b30409c9931a35683c8e6b5105f9c"
+      resolved-ref: "59cc954fc8a66684de0a22353e0981f062e2d60b"
       url: "https://github.com/famedly/matrix-dart-sdk.git"
     source: git
     version: "2.0.1"

pubspec.yaml

@@ -127,6 +127,10 @@ msix_config:
   sign_msix: false
   install_certificate: false
 
+# Guidelines for adding a dependency override:
+# 1. Don't do it if you can avoid it or fix it upstream in a manageable time
+# 2. Always link an (upstream?) issue
+# 3. Explain how and when this can be removed (overrides must be temporarily)
 dependency_overrides:
   # https://github.com/juliansteenbakker/flutter_secure_storage/issues/920
   flutter_secure_storage_linux: