Implement Github authentication to show repositories list (#45)

* Use react-oauth-popup for github authentication popup

* Fetch auth token and use in app to fetch list of repositories

* Get client id and secret from config

* Use GitHub search API for fetching repos

* Use debounce for searching repos and projects

packages/backend/environments/local.toml

@@ -5,3 +5,7 @@
 
 [database]
   dbPath = "db/snowball"
+
+[githubOauth]
+  clientId = ""
+  clientSecret = ""