Decouple core Yaak logic from Tauri (#354)

crates/yaak-git/src/repository.rs

@@ -0,0 +1,10 @@
+use crate::error::Error::{GitRepoNotFound, GitUnknown};
+use std::path::Path;
+
+pub(crate) fn open_repo(dir: &Path) -> crate::error::Result<git2::Repository> {
+    match git2::Repository::discover(dir) {
+        Ok(r) => Ok(r),
+        Err(e) if e.code() == git2::ErrorCode::NotFound => Err(GitRepoNotFound(dir.to_path_buf())),
+        Err(e) => Err(GitUnknown(e)),
+    }
+}